I have to switch between the right-hand toolboxes very often.
Could you create a private toolbox (on the right-hand side) with a zone where you can place a link to the most frequently used function from other zones? Currently, I often have to switch between the Playing Techniques zone (with up/down bow) - Dynamics (Forte, crescendo, piano) - Ornaments (trills, arpeggio). Would be great to be able to create a tailor-made zone in a private toolbox.
I would like that too!
For the panels to just remember the last opened category would already be a giant leap in the right direction…
Unfortunately, one of the next comments is likely going to be: “but, popovers!”… 
It has always been the case that certain workflows and UI facilities enjoyed conceptual preference over others.
E. g. keyboard over mouse interaction, and so on.
I eventually had to get a 32-button stream deck to be productive…
Benji
Stream deck here too… It’s the only way to fly.