The basic idea is that you should be able to override the amount of vertices used for the corners of Visual Elements. Either per-element or globally (or perhaps global with local overrides). Currently, Visual Elements seem to have 4 vertices per corner when the border radius of that corner is above 0. This is okay for elements with small border radiuses, but looks bad when the border radius is larger:
This would also make elements able to look like this, which would be useful in many cases (e.g. futuristic design):
And if there was a per-corner override, this type of element could be achieved:
This could also mean less vertices for small radiuses, and more for larger ones if some “automatic” option was enabled.