Sproket,
For street work (not racing), I'd axe the PC, keep the tre (or disconnect the sensor) in play. It's all, "subtle" not psychological. Busa is detuned stock wise = more ride-able for, Joe-Public. You want the fail-safe setting the tre triggers. That's where you perk the tune to a noticeable, "sensitive" throttle response. Some riders complain of the sharp, crisp fuel quantity the fail-safe sets. So guys wash the ideal (tre = c31) response with more PC fuel to deaden the response. Back to a more ride-able bike... Again?
I hear you about the, "delay" part of it. That's something I can't help you with. I'd make the ECM code attempts first, trying to clean it up. I know the tre set c31, so that's a lot of what c31 cleaned up. Get it? Code 31 cleaned the "second delay," but I'm starting to see JC pounding his head, as he keeps typing... "You don't need a tre"... (Times 7 years and counting).
It sounds like me trying to explain to the, Professor, "the tune is in the fail-safe maps." It ain't gonna happen either. I hear ya, JC.
The Professor does not see the tune is inside the ECM. I have the last laugh. Note how the tre triggers the fail-safe maps. Since 1999, the tune was always on page, 4-9. That's the tuning page for me.
I studied page 4-9, Sproket. If there were no aftermarket parts to trigger the fail-safe code like the tre does, which, "other sensor" would you "unplug" next? Page 4-8 is your helper page. Remember, you can't hurt the bike. The bike is designed to run in either mode. I'd pull that sensor in a heartbeat, just to see what happens.