There have been 1 or 2 or so separated menu alternatives posted on the forum. You may need to make modifications to do exactly what you want...
One of them split Construct and Transform menus.
- Brian

There is MiniSidepane.js, cannot remember what it does. (Not quite what I wanted.) https://moi3d.com/forum/index.php?webtag=MOI&msg=9420.2

SidePane.htm can be modified: https://moi3d.com/forum/index.php?webtag=MOI&msg=6507.386

with a high def monitor, I might like a more separated SidePane of commands, if a talented person would make one.
I would want each submenu to be organized the same, not have some commands moved to the bottom of the screen, or ...
With regular def monitor, there just is not enough room IMHO.