looks like a good idea, would have to sand down to the apex of the curve all along.

another would be to cut the inside cove corner off the shear strip; and still rotate the deck strip in the cove like usual - just raise the deck strip up in yr hand and put it in the cove.

or use a thicker start off strip and not rotate but shape the strip

or use a mitre cut from inside corner of strip at back form to outside corner of front form and have like a diagonal mitre from the form to form. same strip and grain and grain location so would be semi-ok looking.

probably most of the problem is trying to fit a regular bead and cove to an irregular joint , what about starting off w/ a bevel strip or 2 w/ the heatgun

or what about say 3 or 4 parallel longitudinal slices in the strip from form to form or most of the way. saturate w/ glue after the twist. try a razor knife first(no wood loss - prob glues up un noticeable) or a thin razor saw.