We already fully covered this and Morbad has already definitively shown his inexperience in failing this argument.321.6/405 is 79.4%
83.4/405 is 20.6%
104.25/405 is 25.7 damage.
Using your numbers this closely match what is seen in the video.
Although your numbers aren't correct:
PA does 60% absolute damage, 20% thermal, and 20% kinetic. That give damage against a stock hull:
(Also, PA's always do full damage to armor, only when shooting shields do the resistances of the absolute / thermal / kinetic apply, iirc.)
But, like stated: the MC shooting in the way it did was only what caused the additional hull damage.
Other factors (because remember, if your equation factors resistances, then you must up the damage per shot for the negative resistances the FDL has,) such as the admission of a buggy station meaning Morbad is lagging, using repair limpets which we can not be certain repaired to full value, and other such innumerable factors already prove in the arguments side that corrosive will not benefit any weapon but small caliber.
If this were not the case then PvP'ers would run it almost regularly alongside plasma. We do not due to many factors.
In PVE, it's a useful tool for players who already struggle to kill un-engineered NPCs with fully engineered G5 builds. But, in PVP it is redundant and offers no benefit for the average loadout which is why other effects are chosen over it.
Corrosive is only ever paired with gank builds that are designed to shoot low resist traders. That way the corrosive of the all sustain loadouts will actually contribute to the damage dealt.
It's that simple.
So, if we use your math which factors in resists then that more proves me right, not wrong.
Case closed. Thanks for playing.
To be fair, I never expected that this thread would be more populated by non-PVP'ers and argumentation in the face of what is even considered viable in PVP, but that's par for the course as to be expected by those who do not even understand how to adequately fly.