Here is an idea: keep everything like it is but append a number input field where one could adjust the rotation furthermore:
And when 80 degree is manually inserted and one click the 90° degree icon, it should jump to 180 (not 190 in this specific case). Or from 130 to 180. Always to the nearst nth-value of 90… What you think?
This is a great idea. The current rotation transformation are handled using CSS classes, which obviously would not scale to full rotation support. But I have started exploring an approach in this branch. You can see the preliminary results in this issue that I stumbled upon while working on this.
I have also ported this feature request over to the plugin’s GitHub repo and will provide updates there as work progresses.