Im actually a bit shocked that the clutch cant handle the extra power as the miata transmissions have always been overbuilt and is already running more power than the M3W. The transmission was original designed for a truck and I have heard rumors of them lasting quite a long time with power ugrades
Possibly upgrading the clutch to something sold by flyingmiata or otherwise may be the fix? They sell a stage 1 clutch that is rated conservatively at 260 lb-ft at the crank. I know other manufacturers sell far more capable clutches than even this when people supercharger and turbocharge their miatas.
