While there may be some windows limitations, it would be very nice for GUI to have the windows/dialogs that have lots of info to be re-size-able by user....to view more and/or when made bigger that the info gets larger and easier to read
Toolbars in v12 could be "re-shaped" by dragging edges....but capability gone in v15....better to have them back as most all are handy in the tabbed mode since normal floating mode is handy too.
Would be useful to be able to arrange icon buttons along a toolbar...drag to move
Most every program I use has the abilities of above....both 2D and 3D programs....its beyond modern and now an expectation in the GUI and should be easy using windows developer tools....no serious programming needed.