Help with modeling of bevelled surface

Hi folks,

I would like to ask for help with modelling the bevelled surface. I tried to offset curve move down and then make surface out of it. The problem is that when offset is bigger some part of guiding curves will disappear and loft doesn’t work properly for my case. I tried to use “ExtrTaper” but it works only on 2D curves, my curves are projected on double curves srf. It is part of a bigger definition so data tree need to be manageable for the case.

Please see pictures they describe the problem better.


Minimum definition:
bevelled (241.6 KB)

Using R7.