I think you should seriously consider transforming the panels into window space properties in many fixed-size cards that are self-positioned according to the size that windows space properties occupies … for example to the “classic” dimension the cards are placed in column, to the double dimension, two columns are formed, to triple dimension 3 columns and so on … in this the panels of the properties could be used also in horizontal as it was for the beginnings of blender …
take inspiration from the material design of android … to better understand what I mean …