I think you can run as high of a compression as you want with pump gas if you weren't ever going to get on it. You can't make manifold pressure with the throttle closed/barely open. Powerful engines can do 60 mph with the throttle barely open. But if you floor it, it will detonate and that's bad. And it doesn't take the 5 seconds to build heat that you are talking about.

Modern high performance engines have anti-knock sensors to protect them if you put lower octane gas in them than they require. You can drive coast-to-coast with 87 octane gas in your supercharged Demon or your twin turbo Mercedes and it will not hurt a thing, but if you floor it, you can't make max manifold pressure without detonation, so the computer cuts the timing back to protect the engine.

We used pump gas to warm the engine in Big Daddy's Top Fuel dragster. I doubt you're driving a more high performance car than that.