Karma:
My response to your nose-low inverted loop/split-S:
If my E isn't too high a hard roll over, notch or two of flaps and follow you down, throttle adjustments as necessary to avoid overspeed. Going nose-low against an F4U is rarely a good idea, especially in a plane like the Ki-84 whose controls start losing authority as speed builds up. Remember the F4U's roll and elevator response get BETTER with speed, something you can't say for a lot of planes and especially the Frank (though I'll grant you she's more forgiving than the Zeke). Also, power-on WEP the Corsairs really crank it up in a dive, so if you're doing it as an escape you're kidding yourself. The F4U will both exceed your dive speed, and without the control lock/parts shedding.
If I have too much E to follow I go full nose up and immediately begin to roll to keep you centered at the top of my canopy. Proper timing and execution I'm right back on your 6. You're also underestimating der Uber-rudderen (a new Corsair term

). Corsair has one of the best rudders in the game so even if I don't have the E for what I described above, I can still get that nose pointed back downhill for a snapshot before you can come back up through the top of your loop.
Also, the Frank's advantages against the four 1-series Hogs are mostly lost against the -4 (which the 4-Hog is the one this thread was about).The 4-Hog is to the Frank what the 1-series are to the Zeke. She's faster at all altitudes (with and without WEP. In fact, the -4 without WEP will run down the 84 WITH WEP) and will leave the 84 behind in the straight climb at most altitudes, (without WEP Ki has a narrow advantage between 5 and 10k, with the -4 dominant from SL to 5k, and 10k up. On WEP all alts above 7k the Frank won't match) and wins in any contest of energy retention. In low-speed acceleration the -4 is only half a second behind, and the Hog takes over in the mid and upper ranges.
HARDLY cannon fodder.