Merge developable Surfaces?

I think it’s rather complicated to do technically but I simply wondering if you can merge surfaces like in this case it’s a split degree 3 curve and I cannot find a command like ‘_MergeAllFaces’ .
Maybe this would work like a script to ‘detach trim’ surface or surfaces, boolean the resulting outlines and calculate a patch over the existing geometry (curves, points etc)? I know this sounds weired, but I don’t care about total precision but would like to have a 1 click command to recalculate multiple surfaces into one.

Hi Hannes - it is really impossible to say without the surfaces in hand…