Hi Rudy, thanks for posting the example file. That seems to be something going wrong with corner mitering. I'll see if I can track down why the miters are not behaving well there in v3 but it's a generally difficult area to intersect 2 surfaces that come very close to being tangent to one another but are only a few degrees off, which is what you have here. The segments of your curve there are close to being tangent to each other but are just not quite smooth, about a 1.7 degree difference between them.

The sweep mechanism sees that is not a smooth juncture there, and it extends the surfaces and tries to intersect them with each other, and it's not all that unusual for that kind of barely grazing almost tangent type of intersection to be difficult to calculate.

If your other cases are similar with strange long sections poking out, those are likely to be the same problem - if you get the curve to be smooth in those areas rather than just slightly kinked it should get rid of those kinds of problems.

- Michael