Just curious how useful this “grouping” would be for you. You did not mention this in you last post.
KiCad has grown quite a lot in the time I’ve been using it (maybe 5 years?) and the speed of development is accelerating over the last few years. A few weeks ago I installed V5.99 mainly for getting to know it’s new features and for finding and reporting bugs, and Lots of things have been added or improved in V5.99 (soon to become V6). A nice overview of the changes are in the thread below, which has accumulated over 300 posts in a year and a half.
But still. there are quite some things that would sound logical but are still missing. Support for circular tracks for example is just now slowly getting some support, while you would expect it to be standard. There is an open request for teardrops which has been in the bug tracker for 12 years.
There are some scripts for teardrops, but as of yet none have been directly integrated into KiCad.
The “grouping” looks like it’s already a useful feature, an in the long run I sort of expect it to be used to integrate sub projects such as your “power supply” example in other projects. Sub assemblies and multi PCB projects are not yet part of KiCad. Same for panelisation. There are some scripts for it, but no (real) integrated support in KiCad itself.
As an open source project, development is probably a lot more chaotic then for a commercial project. I have no close ties with “the developers” and have no insight into the priorities. (There is a roadmap)
If you want to look into time saving features, then have a look of the 60+ “side projects” around KiCad on: