Hello Barrie,

I have tried to find a simple solution for your problem. It is not perfect, but maybe a startpoint. I have extended the main surface (blue). Then I have made an extrude (red). After that I made a curve for the extrusion oft the cyan surface. Then trimmed the blue one. I have add a trimmpoint to the edge of the blue and made a blend between blue and the red surfaces segment (bulge 0.6). The result of the blend is green. After all I have made a sweep with profiles from the edge of the green and your main surface (don't forget to insert also a trimpoint) and two rails from red and blue. The resulting magenta may have some deviations in continouity, but I thing very small. You have to play with the shape of the cutting surface and the bulge to find a solution that fullfill your needs;-)






Have a nice day
Karsten

p.s.: You should avoid the small patches in your base surface, that would make your life easier;-)