Naresh Patre
Ansys Employee

Hello Roberto

I went through the video to understand the issues. Regarding the first one, extended joint is applied first and then the 2D triangular relief is being created. I think this wont work because the relief faces are not separate but overlapping each other.

Regarding the 2nd issue (It is not possible to unfold a sheet with triangular relief and extended joint) I think this is a bug. 

I have submitted BUG 403403 and mentioned both the issues. I will let you know once they get fixed by the development team.