add to .desktop file?

[clumsyfingers]

hi
im just toying with the idea of adding the gdbus command to a desktop file
something like:
...
Icon=firefox
Exec=gdbus call --session --dest org.gnome.Shell.Extensions.awsm --object-path /org/gnome/Shell/Extensions/awsm --method org.gnome.Shell.Extensions.awsm.Autostart.RestoreSession
...
how do i differentiate so that this .desktop file only launches firefox in its pre-defined position(if i have a saved session with only firefox) and another that will similarly only launch thunderbird (with a separate tbird session saved) ?
is it even doable...cos every desktop should have this imho
im on wayland btw and latest gnome etc

thanks for a great extension that makes gnome a liveable place, but if i got the stuff above working it would be even better