Clutch problems / dilemma

[P71]

So I installed a new Zoom MU-Series OEM clutch in the RX-7 last August. It's been autocrossing a bunch but only drag raced for 5 or 6 passes. It has maybe 4,000 miles on it total. Tonight the clutch pedal wouldn't release at the strip so I coasted and by the return road it was fine again. However now the clutch chatters like crazy on a dead-stop start, but doesn't make any noise once moving. It drove the 50 miles home A-OK and goes around the block stop/starting just fine (except the noises). It also smells faintly of burning clutch.

I called Summit (who I bought it from) who informed me they only have a 90-day warranty. Suck! Should I pull it and see what happened or??? I've broken plenty of clutches and it honestly feels like it literally just fell apart (shoddy materials/workmanship). I know it's seen "hard use" being in a sports car and autocrossed, but it still shouldn't just fall apart.

Any ideas? Suggestions for a better replacement?

Freaking autocross tomorrow too!