Johannes, if you are feeling brave, you could try packages that will appear in the project mentioned in the description, downloadable from here:
https://download.opensuse.org/repositories/home:/badshah400:/nextcloud-desktop-vfs/openSUSE_Tumbleweed/

They hopefully implement the vfs-plugin correctly.

(In reply to Atri Bhattacharya from comment #0)
> 1. Either delete the vfs_* files, or 
> 2. Split out a separate package (which should sufficiently warn users to not
> try it) for the vfs plugin.

I strongly support option 2.
In my opinion, VFS support is more or less essential - especially for large cloud storages.

(In reply to Atri Bhattacharya from comment #1)
> They hopefully implement the vfs-plugin correctly.

Thank you very much! The package works exactly as it should.

The warning is sufficient in my opinion. The formatting is not quite right yet (when installing with zypper), there are probably line breaks in there that could be omitted.

"The virtual file system implementation of nextcloud-desktop on Linux is at an early       experimental stage. Please understand the risks before installing this package:             https://docs.nextcloud.com/desktop/latest/architecture.html#virtual-files"

(In reply to Johannes Studt from comment #3)
> (In reply to Atri Bhattacharya from comment #1)
> > They hopefully implement the vfs-plugin correctly.
> 
> Thank you very much! The package works exactly as it should.
> 
> The warning is sufficient in my opinion. The formatting is not quite right
> yet (when installing with zypper), there are probably line breaks in there
> that could be omitted.
> 
> "The virtual file system implementation of nextcloud-desktop on Linux is at
> an early       experimental stage. Please understand the risks before
> installing this package:            
> https://docs.nextcloud.com/desktop/latest/architecture.html#virtual-files"

Appreciate the feedback. I fixed the message formatting and added a README file to outline further steps needed to enable the plugin. Will submit this to Factory if you are happy with how it stands now.

(In reply to Atri Bhattacharya from comment #4)
> Appreciate the feedback. I fixed the message formatting and added a README
> file to outline further steps needed to enable the plugin. Will submit this
> to Factory if you are happy with how it stands now.

Sorry for late reply.

The message formatting is fine now. The README file is informative and sufficient.
Number 4 is not entirely correct in that the option also appears for existing user accounts as soon as the ExperimentalOptions have been activated.
But perhaps it is safer to guide the user to create a new account to test the feature.

For me, that's absolutely fine. Thanks a lot for your efforts again.

(In reply to Johannes Studt from comment #5)
> The message formatting is fine now. The README file is informative and
> sufficient.
> Number 4 is not entirely correct in that the option also appears for
> existing user accounts as soon as the ExperimentalOptions have been
> activated.
> But perhaps it is safer to guide the user to create a new account to test
> the feature.
> 
> For me, that's absolutely fine. Thanks a lot for your efforts again.

Yeah, number 4 is more a safety guide than strict necessity, but let us leave it in as a recommendation nonetheless.

With this, I consider this feature as completed.

I am deeply grateful to you for starting the discussion about it and pointing to the correct steps needed to make it possible. I had not known about them before you pointed them out, big thanks.

(In reply to Atri Bhattacharya from comment #6)
> With this, I consider this feature as completed.

Yes.

Just a short question: You uploaded new packages to your test repository yesterday (version 3.13.0-5.1).
Did you change anything compared to version *-4.1? Since installing this version, the sync or the preparation for the first sync after starting the client is extremely slow. The log is full of messages 
> Ignoring spurious notification for file XYZ
I don't know if this was the case before, but I think the first sync was orders of magnitude faster.
I would like to test this again, but unfortunately I no longer have the *-4.1 packages.


> I am deeply grateful to you for starting the discussion about it and
> pointing to the correct steps needed to make it possible. I had not known
> about them before you pointed them out, big thanks.

No, thank you. You're welcome.

(In reply to Johannes Studt from comment #7)
> (In reply to Atri Bhattacharya from comment #6)
> > With this, I consider this feature as completed.
> 
> Yes.
> 
> Just a short question: You uploaded new packages to your test repository
> yesterday (version 3.13.0-5.1).
> Did you change anything compared to version *-4.1? Since installing this
> version, the sync or the preparation for the first sync after starting the
> client is extremely slow. The log is full of messages 
> > Ignoring spurious notification for file XYZ

Nothing that should cause this. Here is the change from revision 5:
<https://build.opensuse.org/package/rdiff/home:badshah400:nextcloud-desktop-vfs/nextcloud-desktop?linkrev=base&rev=5>

Maybe it is your sync server that may be working slower than usual or something network related. Please let me know if the problem persists. Could just be an issue with 3.13.0 itself.

> I don't know if this was the case before, but I think the first sync was
> orders of magnitude faster.
> I would like to test this again, but unfortunately I no longer have the
> *-4.1 packages.
>

Operationally, there should be no difference between 4.1 and 5.1 packages as the change was only a typo fix in the .changes file.

Realised that(In reply to Atri Bhattacharya from comment #8)
> (In reply to Johannes Studt from comment #7)
> > (In reply to Atri Bhattacharya from comment #6)
> > > With this, I consider this feature as completed.
> > 
> > Yes.
> > 
> > Just a short question: You uploaded new packages to your test repository
> > yesterday (version 3.13.0-5.1).
> > Did you change anything compared to version *-4.1? Since installing this
> > version, the sync or the preparation for the first sync after starting the
> > client is extremely slow. The log is full of messages 
> > > Ignoring spurious notification for file XYZ
> 
> Nothing that should cause this. Here is the change from revision 5:
> <https://build.opensuse.org/package/rdiff/home:badshah400:nextcloud-desktop-
> vfs/nextcloud-desktop?linkrev=base&rev=5>
> 

I realise that you would need to login to see this; anyway the change between revision 4 and 5 is as follows:

Index: nextcloud-desktop.changes
===================================================================
--- nextcloud-desktop.changes (revision 4)
+++ nextcloud-desktop.changes (revision 5)
@@ -2,7 +2,7 @@
 Wed Apr 24 14:36:05 UTC 2024 - Atri Bhattacharya <badshah400@gmail.com>
 
 - Split out a nextcloud-desktop-vfs-plugin package.
-- Add README.vf.md file outlining steps needed to enable
+- Add README.vfs.md file outlining steps needed to enable
   virtual-file system plugin.
 
 -------------------------------------------------------------------

(In reply to Atri Bhattacharya from comment #8)
> Maybe it is your sync server that may be working slower than usual or
> something network related. Please let me know if the problem persists. Could
> just be an issue with 3.13.0 itself.

I updated NC to the just now released 28.0.5, restarted php-fpm and apache2 und tried again, and it just works now.
Please excuse the confusion.

Now I only have one “micro-issue”, but I may open a new report for that:

NC Client recreates the old config directory ~/.local/share/Nextcloud at every startup and creates the file Cloud_sync.log in it.
When restarting, NC Client tries to migrate the incorrectly recognized old installation to ~/.config/Nextcloud, but of course this fails.

> hannes@cadpc:~> nextcloud
> nextcloud.gui.application: Migrating old config from "/home/hannes/.local/share/Nextcloud” to “/home/hannes/.config/Nextcloud”
> nextcloud.gui.application: Failed to move the old config directory to its new location ( “/home/hannes/.local/share/Nextcloud” to “/home/hannes/.config/Nextcloud” )
> nextcloud.gui.application: Will move the individual files ()

Apart from that cosmetic failure, everything works fine. :)

(In reply to Johannes Studt from comment #10)
> (In reply to Atri Bhattacharya from comment #8)
> > Maybe it is your sync server that may be working slower than usual or
> > something network related. Please let me know if the problem persists. Could
> > just be an issue with 3.13.0 itself.
> 
> I updated NC to the just now released 28.0.5, restarted php-fpm and apache2
> und tried again, and it just works now.
> Please excuse the confusion.

Glad to know.

> 
> Now I only have one “micro-issue”, but I may open a new report for that:
> 
> NC Client recreates the old config directory ~/.local/share/Nextcloud at
> every startup and creates the file Cloud_sync.log in it.
> When restarting, NC Client tries to migrate the incorrectly recognized old
> installation to ~/.config/Nextcloud, but of course this fails.
> 
> > hannes@cadpc:~> nextcloud
> > nextcloud.gui.application: Migrating old config from "/home/hannes/.local/share/Nextcloud” to “/home/hannes/.config/Nextcloud”
> > nextcloud.gui.application: Failed to move the old config directory to its new location ( “/home/hannes/.local/share/Nextcloud” to “/home/hannes/.config/Nextcloud” )
> > nextcloud.gui.application: Will move the individual files ()

https://github.com/nextcloud/desktop/issues/6201

https://build.opensuse.org/request/show/1170327 accepted into Factory