well, technically that's possible - yet what for?
It's not productive to enable/disable toolbars each time.
On the contrary, it's simpler to create workspaces (user-defined layouts for UI) for different tasks and switch between them when needed.
The only thing that they are supported in 2.2.2 alpha (dev version is located there
https://github.com/LibreCAD/LibreCAD/releases/tag/2.2.2_alpha-latestMore information how to use workspaces may be found there:
https://youtu.be/FwvXs1eDYBAThus for quick adjustment - current functionality is fine, and for specific tasks (like viewing/reading, ordinary drawing, dimensioning etc) - workspaces are more convenient, as for me.