What @zebulon said make me think about detached gramplets and the possibility to save them and to reopen gramps with that gramplets detached again at the same screen position they was before closing Gramps.
I’d published that screenshot of the desktop I was using but I don’t use it anymore because it’s too boring to reopen Gramps like that every times I restart it.
Ideally, it would be great to have the possibility to save display positions and then to be able to recall one or another saved positions with different gramplets: one for editing persons while browsing sources, another one for some other actions… etc.