You can order Nesika actions this way. I believe you could speak with Defiance and do the same. Bat too, however they often use a bolt shroud that's lug'd/keyed rather than threaded into the bolt. Your 3p safety likely wouldn't work unless they made the bolt accordingly.
In a pinch:
I could take an existing action, machine a filler block where the safety inlet is, silver solder in place, contour & blend, and you'd never know it after cerakote. Yes, it'll affect the heat treat of the steel a bit. Note however its on the opposite end of the "business side" of the action. Long story short, it's not going to hurt a thing.
It'd be a bit unconventional for sure, but I'm confident I could pull it off with no consequences.
Kick it around if you get stuck on ordering the action w/o the feature machined.
C.