Negative soak applied twice with supplemental dmg

[Khaze]

Prefacing this by saying this almost certainly not a bug. I'm sure this works exactly as it was built. However, I can't believe this is what was intended (or even if it was, I feel it warrants reconsideration.)

Negative soak from blood frenzy (and presumably every other skill that provides negative soak) gets applied twice when attacked by something that provides supplemental damage. Blood frenzy is the extreme case here and the source of my woe, since a full stack of frenzy normally incurs a -8 soak penalty, but the way supplemental works, this -8 soak gets applied for both calculations and becomes 16 extra damage taken.

- Gee Wiz (ID 13180) attacked you (ID 2258) with a Clockwork Blade and hit for 17 points of slashing damage. Their clockwork blade crackles and sparks with electrical energy, shocking you for an additional 14 points of electric damage! This was enough to kill you!

(actually looking at the calculation, I'm pretty sure I'm taking 2 points less slashing damage than I should be, unless the seraph in question was under -2 damage from some source)

I have no delusions about the potential of a full frenzy stack, but +16 damage taken is egregious and makes a risky trade an impossible one. -8 soak is already a steep price to pay and certainly makes you reconsider when attacking auras or pets. -8 soak when fighting actives, especially ones with an aura, is an effort tantamount to suicide. But -16 soak? Too much damage to even react to.

Supplementals can't normally be stacked or even buffed as far as I know, but on the receiving end it seems it is possible to enhance them. I believe it would make sense and be fairer too, if negative soaks were tracked separately from the soak table and only applied one time. Whether it gets applied in the usual order as other damage (supplemental first, then rolls over the extra to primary if any was left over) or simply divided evenly between is subject to debate.

[Goliath]

I see this as another argument to go for a design with mostly resistances and a few rare soaks for tanks, rather than the opposite.
Meanwhile, I'd suggest supplemental damage to bypass a percentage of soak equal to the percentage of effective damage from the main attack (basically, effective damage / nominal damage). Would allow supplemental damage to decently bypass soak if the base attack hits well, but would be weak if the base attack hit for tickle damage.