@neauoire
it could be implemented as a custom 'window' device that the menu rom would send DEO calls into.
There's enough space for x,y,width,height and probably some flags that would set if the rom's window can be moved or if there should be a border drawn around it or not
I'm not sure if this approach would be in spirit of porporo though
@kelp porporo has no custom devices at the moment, I'll try to see how far I can get without having to do make new ones.