My suggestion regarding the design studio and tree, would be to have it in both places, when you click on the design studio, it redirects to the tab on “Research”. This would overcome “moving” it to somewhere else.
Much like when you click on a research facility, it takes you to the research page.
EDIT: You also have a Z order bug, if you look at the video at 7:14
Currently what I have done (for the next patch) is have the tech tree in both places. Its small, so it fits in the window that the design studio brings up, but its also shown in the main R&D screen, but I do wonder if I should just dump that and make it link purely to R&D screen with that tab selected…
I know there are some annoying Z order things, I’m not prioritizing them yet