Gunbreaker, Bloodfest.

[baklava151]

Gnashing fang combo could grant a self defense buff to reduce the APM when a tank buster happens in a 60s window

I wouldn't hate it but it's not really necessary. Once you get an idea of when TBs happen during a fight, you can prepop Nebula/Rampart before your 1-min starts and usually have a least one weave slot for Heart of Corundum. Worse comes to worse you move some things around to make room for mits but unlike DRK you at least have a bit of flexibility there.

Rampart and Camouflage could be merged, the latter is a bit niche

I've only just cleared P9S but looking at logs from later fights, with the exception of P12 it looks like the bosses do a lot of physical autos which Camouflage is perfect for and lets you save Nebula/Rampart for TBs. Plus it's nice in dungeons for trash pulls, so it'd be a huge downgrade to get rid of it.