I suggest making the properties and layers panels embedded (instead of separate floating windows) and accessible via a button located in the header, as in many Gnome applications? It seems to me that this would be in the spirit of your application, very minimalistic and compact (all in one window). This could be made an option so that it would be possible to keep the previous command.

I suggest making the properties and layers panels embedded (instead of separate floating windows) and accessible via a button located in the header, as in many Gnome applications? It seems to me that this would be in the spirit of your application, very minimalistic and compact (all in one window). This could be made an option so that it would be possible to keep the previous command.