Problem Fillet

Should I do a fillet of 0.3 along the red border.
I think that this kind of fillet are difficult to solve in Rhino, in fact, the result is not acceptable.
You will be able to better accommodate these kinds of situations?
fillet problem.3dm (570.4 KB)

With forms like this I find it’s best to start with a valid solid polysurface. Then use the solid fillet edge or blend edge commands. Running these fillets in the correct sequence is essential. However your form has topology along the red edge that should be avoid as much as possible. Blending those surfaces is very tricky.

This is the way I would blend those surfaces together. I would still recommend avoiding this topology as much as possible.

Thank you Stratosfear, if you do not mind, I’d send the 3dm file, so I try to play it and study it in more detail?