its a symlink … you’d have to change the kernels filesystem handling here
that would be something to ask freedesktop.org about since it would be a change to the XDG spec …
i still dont understand … if you want to use per-user .desktop files because one of your users needs an extra option added for launching, you’d copy the file to ~/.local/share/applications and edit it to have current in there while you add the option …
if you actually mean multiple parallel instances of a snap, you already have to define a namespace when installing the second (or N’th) parallel instance: