This bug has a huge impact even at high regen levels. The main problem is that BH attacks cost 4% less energy, in a long term PVP or PVE engagement, that means the trooper will be forced to use the auto-attack more often just to remain in the high regeneration level, which results in a DPS or HPS loss.
I've already checked for rounding. If you mouse over your ammo bar, it's shown in terms of percentage, which can easily be compared to heat. 25% Ammo = 100-75 Heat (25 heat left over)
A fix to this problem should be relatively simple, All abilities that cost 2 Ammo should be reduced to 1.92 Ammo
1.92/12 = .16 which is equal to 16 Heat
All abilities that cost or grant 1 Ammo should be reduced to .96 Ammo
.96/12 = .08 which is equal to 8 Heat.
What proof is that?
All that % is showing is ammo translated into % in steps of 1/12.
You keep referring to the number of pips as if they are based on a different regen formula.
If they are using the same regen as a BH but not displaying a whole ammo until it can be rounded up in a step of 1/12 then the regen is exactly the same at all times.
The same applies to the costs, 1 ammo doesn't have to be 1 ammo.
The only proof in any of this is a dev reply on internal mechanics (and pigs might fly) or some extremely tedious testing by hand.
You believe that Troopers pay more for their attacks.
This is provable, set up a macro to click at a fixed interval so that both classes slowly drop into lower regen.
Over a long enough period of time the one with the highest cost will dip into lower regen first and this can be seen on a combat log as less attacks.
Unless of course my theories on them being identical are true in which case they will never differ because it's all just a graphical rather than a mathematical difference in their action points.