Umm, if his comps are positive, then it will get richer after a reset. Comps are always zero on reset, so as it learns the positive compensations, it will get richer.
If you tune the fueling table without scaling the MAF, then since you've tuned it with comps near zero, it will run rich in OL when the ECU learns to be richer in closed loop.
You're correct that he didn't raise the D range spec, I missed that. I know the JDM version 8 ROM has significantly lower thresholds for CL to OL (max throttle % for open loop is barely over 30% while USDM has most cells @ 70%). Base pulse width OL trigger for engine load is also significantly lower than USDM @ 3200+ RPM. I would assume the version 7 ROM he's using is similar. It could be that his ROM can't hit 50+ g/s in closed loop, which would prevent long term trims from affecting the open loop map... or it could just be he hasn't driven enough of that for the ECU to learn trims in that range.