If one were to increase compression for an NA application, what is the maximum compression ratio the OE ITR ECU can handle without ANY additional fuel control electronics and/or timing adjustment from 16 deg?

I ask this because many of us looking for more NA power usually increase compression. So what happens when your ready to sell the car?

Many people advocate a 12:1 ratio with tuned ECU/stand-alone, but what happens if the car must be sold? Most of us would strip the aftermarket parts and return the car to stock for an increased consumer base. Can't exactly do that to pistons! I assume JDM 11:1 would be fine. Probably not worth the trouble though! Could one get away with that and a thinner head gasket for around 11.3-11.4:1? Maybe 11.5- 11.8:1 Endyn RW since they enhance combustion?

Please enlighten me!