This would have to be split into two things:
- shifting ecosystems on the list (which would need at least one button to open some kind of management window, or two +/- like in scopes) but there's not enough space in UI for that I guess)
- putting ecosystems in some kind of virtual wrapper building a tree - actually mimicking the typical Rhino Layers here
This sounds reasonable but it would need more time than one could imagine. Not saying no but certainly not now. This is something to consider in a late major update or even maybe for v2 as this may bring inconsistencies in I/O when saving data to *.3dm file, and it could cause a break with older scenes.