@frederik Oh interesting!
After some thought, I wouldn't lock the vertical line to 90 degrees because after you've set the baseline, I'm not sure you'd want your horizontal movement of the x-height point to unexpectedly change the decided baseline setting. Having the angle of the x-height line only react to the baseline points makes sense to me.
In terms of UI interaction, the only thing I'd change from the public release is to not draw the vertical line (or maybe draw a lineDash if anything), as it doesn't seem to correspond to any UI in Glyph View. Otherwise, I think it's less about the UI than the unexpected resulting transformation.
