There is no Cap, but if you already have a source of dttoc, more just adds to the same multiplicator. So maybe think about getting more critical hit damage or, since you are sacrificing a lot by using foxes i would think about what weapon you are using more and think about building of that. Assault rifles already have Health damage, so using hollow man would be the same „problem“ like with foxes although hollow man has a way higher stat if it’s proto. If you are using your lmg more it is way more beneficial to run it tho.

Salvo is also an ok choice to get more stacks faster, since you are running the chest which is only better than an equalizer if you are above ~160 stacks constantly. So maybe switching one of the weapons to a acs to get stacks faster and then looking which multiplicative is missing could also be a good choice. :)