Set a minimum number of workspaces to exist at all times. Any additional workspaces are still created and removed dynamically.
[Fork from https://github.com/philbot9/gnome-shell-minimum-workspaces]
40+
As this is a non-official fork until upstream version is updated, currently only install via git is suggested. Do not use this version if you do not dare to use git or want an official release.
cd ~/.local/share/gnome-shell/extensions
git clone https://github.com/theseer/gnome-shell-minimum-workspaces.git minimum-workspaces@philbot9.github.com
Note: This will replace the original upstream version in case it got installed the same way.