Hex Panelling Surface help - Grasshopper

Hello all, hope you can help me.

I’ve developed a very simple grashopper script in order to make a sort of vault hex ceiling from a surface, as seen in this screenshot.

Everything was fine, until I was told I had to modify a section of it. The thing is that at first, it was a single segment that I could do with just one surface, but now, it’s a “Y” shape segment, it has a bifurcation and I can’t manage to make it with just one surface. Here’s a screenshot.

As you see, I have to make into two separate surfaces. and I have a major problem at the joint of both ceilings, I need to fix this in order to make it smooth.
Another solution I’ve tried is extracting the wireframe and making a single surface with a patch. I get a single surface indeed, however the UV values are all orthogonal and don’t follow the shape of the vault as the original case (besides for some reason I can’t cut it), so this solution doesn’t work for me.

What I need is basically what I’ve done with the two surfaces but with a clean join.
Can anybody help me with ideas or suggestions please?

Thank you very much.
HexCeiling_v2.gh (209.7 KB)
HexCeiling_v2.3dm (720.6 KB)