Curved surface has non orthogonal uv coordinate

I have a curved surface using sweep 1(2 unparallel curves). How can the uv on the surface be orthogonal instead like curved in the reference image below ?
2965_Curved Surface (6.7 KB)

rebuilding the surface in rhino or with a plug in like lunchbox, or if you want to stick to vanilla gh you could rebuild the boundary curves and than make a new srf :

Edit: Better rebuilding the curves before the sweep

Normally relying on UV coordinates for the grading of a surface is far too limiting. Take a look at this thread for some ideas on getting control of the grids: