I would like to be able to rotate guides by typing +/- and numbers into the guides’ angle field just like I can with node positions. This would be useful rotating guides in measurement mode to measure the angle of a diagonal stroke while I change it: match the guide to the angle of the stroke, rotate it +90°, and I can use it to see the stroke width.
Not sure if this solves all your needs, but: did you know you can double-click the “handle” of a guide to change it to its perpendicular angle?
Good point! For some stupid reason I never actually used that feature when the guide wasn’t orthogonal.
I tried to fix the calculation in the angle field. It is a bit bigger operation…
You can use the up/down (+shift) cursor keys to change the value.