A lot of the aircraft in AH have "WEP" that doesn't require an additive. That is, they just run at higher RPM and manifold pressure, that's where they get the extra power.
Some require a coolant or anti-detonating additive for the increased pressure. The F4u4 uses water, as does the P47N. The 109K uses MW50.
Most of these planes have the reserviors in centrally located tanks, tanks that are well balanced and do not affect flight performance, empty or full.
The Ta152 uses MW50 and GM1, one in the tail one in one wing. Those are two places opposite of "centrally balanced".
I know that no aircraft drains the tanks, but no other aircraft has the same problems with the tanks, so a compromise should be reached with the Ta152, rather than an across-the-board sweeping change.
Oh, and Moot, HTC faculty read the forums regularly. That's part of why I bring up issues like this.

EDIT: In AH1 this thing was a secret monster. However, AH1 had inaccurate air flow and this might have been why.
Hell, I just realized. If it was tailored and tweaked to fly in the buggy code, why don't they tailor and tweak it to fly in the new code? Get the same results but with the new airflow code?