I think I have seen ONE failed stainless reed in 40+ years of building engines. Perhaps 50-100 failed fiberglass, and 25-30 failed CF reeds.
I think the best route is to punch a bunch of 3/16th holes in the stainless, and back the holes with 0.2mm CF reed blank to make a solid 2 stage reed.
That will provide much better low end, and retain the top rpms. I'll post up when I make mine in a few weeks.
Edit:
sandwich the stainless between two sheets of 1/8th in steel to prevent distorting the stainless. Clamp it tighter than F8ck...