I'm trying to get time over to test Macc now that there are so much out there, but I still feel like my samples are bit low (but also not as amazing as I'd want).
600ish base 75 BPs seem to do 300ish damage on tiamat with 16 macc. This is really no difference from when my 500 base nukes did 250ish damage with 9 macc, so it doesn't seem like it has made any difference here.
Varied a bit between 750 and 1000 damage (base on my level 5 BP), so I guess 75%-100% damage. Sadly I never tested these things out much before so not sure if this has improved, or if it also is more or less as before.
I only tried 1 roar but it actually landed. Remember these getting resisted often so this might have benefited from the high (17) macc I had.
Wondering if anyone else picking the Macc body has seen any difference, or if perhaps it would be worth another augment. Perhaps Macc does more for the debuffs on BPs than on actual elemental damage resistance.