Nevermind. Instead I started messing around the the TankDamageModifier plugin thinking it should be able to work for every other Si with a few adjustments. And turns out it did!
Wasn't able to find any cvars available for adjusting the Claw (secondary) attack damage on any of the Si. The only ones with some relevance I found are these:
boomer_pz_claw_dmg (default 4)
hunter_pz_claw_dmg (default 6)
spitter_pz_claw_dmg (default 4)
smoker_pz_claw_dmg (default 4)
jockey_pz_claw_dmg (default 4)
But I wasn't able to see any results with these after testing many different values with all of the Si.
So, if anyone is able to make/find a simple plugin that allows adjustment to the Claw attack dmg of every si I would be very thankful.
The only ones I've seen so far in comparison to this were for the
Tank, and
Common Infected. So, I'm hoping something like this is possible.