OK. Boxes have max capacity fill, conduit, etc.

What about MC/AC wire. Is the *clad* good enough on how much *capacity* the wire inside needs.

I plan to put a 4" square box on a wall that has been mudded/rocked over.
It's roughly 1 1/4"+ in depth so to make this fairly seamless, I plan to channel out the wall, run the BX in the channel and then plaster the BX in place. I plan to take a chipping hammer and chip out the area where the box will be so it sits flush with the wall (poured concrete wall).

Is is ~okay~ to bury the wire in plaster ?
Or does it need room/air around it.