When I draw a circle in Draw (using millimeters as the unit), I can set the size to whatever I want. However, when I resize a circle with a diameter of 5.08 mm to 5.00 mm, deselect it, and re-select it, the diameter is back at 5.08mm. Playing with the sizes a little more shows that the size “sticks” again at 4.83 mm (i.e. 0.25 mm step size). Is there indeed a 0.25 mm step size internally? If so, is there any way around this that allows more fine-grained size changes?
It seems to me, that the field in the sidebar shows wrong values. If you look at the size field in the status bar or if you use the Position&Size dialog, they show 5,00mm as expected. I think, it is a bug with the sidebar.
The internal accuracy is 1/100 mm.
You are absolutely correct. In fact, I found that a bug was filed for this unexpected behavior of the sizebar: https://bugs.documentfoundation.org/show_bug.cgi?id=99711. I’ll try to make some time to help out fix this bug.