I just fixed the angular dimension issue for arrow size = 0 and tick size > 0.
https://github.com/LibreCAD/LibreCAD/commit/50805858095c100b093da76da3e47c52ac9983e1This only affects nightly builds for Windows and further versions.
I don't expect back ports to older Linux versions, so @Lambertus this sadly doesn't affect you.
You can try my above workaround, to set arrow size to 0.001 to solve this for 2.1.2.
For my other mentioned issues I created github issues
#1328 and
#1329.
investing less than half an hour into Search function can save hours or days of waiting for a solution