Les , let me see if I have this right ? Originally this was said to be a bolt right on item to improve engines performance , now I'm reading that you must reset your engine squish clearance to .005 ? To see gains over the stock head button.

Am I correct ? The Button I have here already has pitting from Detonation and it's been used with 87 so Iam a bit confused where the advantages are hiding

Bolt-on for the QDHT and the QDP with a stock stroke there is a significant improvement, however the stroker engines one has to set the squish clearance and as mentioned .0025"- .005" squish is recomended. The detonation you are getting is more than likely from excessive squish clearance and the Toroidal head is not performing to it's full potential...talk to your engine builder on engine assembly.

If there is detonation how soon will it show signs of pitting ? 10 min an hour or more ...

Nic- Detonation can be severe, mild to the occassional occurance.
The following issues can cause detonation even with a Toroidal cylinder head without changing the fuel octane and since the Toroidal head is not detonation prone, however it is still possible
Excessive heat causes detonation in a two stroke engine
The lack of cooling will cause engine overheating or run hotter and that can lead to detonation by elevating combustion temperatures
A large squish clearance with high compression doesn't cool the end gases enough to prevent detonation
Low squish velocity enhances detonation