I don't know much about flame propogation. I believe that the flat piston delays the propogation thus reducing detonation. Is that right? I do know that it is imperative that quench be around .040 to work effectively. Your 2 senario's do not give that dimention. I've read other posts that anyting over .050 is a waste of time as it will detonate. Detonation reduction with high CR is the main goal of quench. Iv'e run higher compression with .040 quench and seen no detonation. I'd stay with this number a all costs. Not sure about dished pistons, but with flat tops it does work.