well your pushing the limits with pump gas even with aluminum heads.
I will take a guess and say the ignition system is computer controlled closed lop system that constantly monitors engine spark and knock, detonation, and pre ignition.
If the computer see's one of these problems it will just pull a bunch of timing out of the engine to help out. This is bad for performance. Lets say the same engine with less compression around (lets say 10:1) now has the same thing going on but the computer doesnt see any spark knock. The engine is operating at full potential and optimal timing. The lower compression engine now will out run the engine with more compression every time like this.
My 01 SS Camaro would detect a knock and pull timing out until I fill the fuel tank up. This is a decade old technology BTW.
On out V-8's a engine making good power at say 34-36 deg total timing will loose a easy 5% maybe as much as 10% if you pull the timing down 10 deg to 24-26 deg easy.
So in this case the increased compression's gain in power is offset more by the now none optimal timing curve...
Plus nothing will kill a engine quicker than pre ignition, and detonation.
Just some food for thought.
Later
Bob
Just drop my old engine in between the Honda's fenders and dont worry about it

ive actually taken some measurements for my rb into the 2000 lb honda... i would have to take the firewall back like 16 inches and make a huge tranny tunnel.... then i have a short wheel base and that does not seems super stable at high speeds. but ive thought about it.

a crank with 5mm longer stroke and the rods to go with it with my stock pistons

Are the rods 2.5mm shorter than stock?

Some reason those little motors always seem to be able to run way more compression than our big motors, I used to work at a Honda dealer and all the tuner guys working there were typically running 12 to 1 or even more on pump gas with ZERO issues, heck my dads 97 Geo metro would crank 220 PSI bone stock and runs better on 87 than 93 I think it has to do with the aluminum motors preventing hot spots, tiny bores and high RPM they would turn but somehow they got away with some crazy cylinder pressure