Hi Steve,

> I will just need to accept that MOI cannot boolean these types.

Yes, there is currently a bug in the surface/surface intersection mechanism when 2 tubular things cross each other and intersect at a single top "crown point".

I think it will be possible for it to be improved in the future.

But for now the easiest way is to have a slight alteration in the tubes so that they do not intersect in that particular way - your lower accuracy sweep result happens to be one method that will do that, making a slight difference in the tube radius values is another way.

- Michael