Don't know, sorry but if you are experienced with OA then disregard the comment.
I am certain that in one of the manuals I have read DJI said that, for that drone, OA was automatically switched off during either or perhaps both, an automated landing and or the RTH automated landing but I have never been able to find that again.
OA, if on, is probably not a problem during a pure vertical descent from RTH height, (check the manual ) I rarely, if ever, use it full stop - hence probably, but my problem stemmed from being low and trying to move horizontally, OA saw the hedges, trees, house and probably me.
OA as such is horizontal and UPWARDS. The downward looking sensors are classed as a different system, VPS & perhaps you could include landing protection with VPS though landing protection uses emitted IR whereas VPS and OA use visible light.
OA will not stop a landing but VPS can, if it dislikes the landing area, I've seen "no sir I'm not landing there" a time or two.
Sideways looking OA is, from memory, only on in Tripod mode and not as good as the fore aft OA so be careful with it.
"OA as such is horizontal and upwards" brought to mind one other thing, I don't know if the mavic 1 has it.
The
mavic 2 has an upward looking sensor that is normally on, even if OA is off. It's a curse indoors, this sensor is only switched off in sports mode.
This sensor exerts a LOT of authority, taking off in daft places I have had it limit the drone's height to a couple of inches, I am not kidding.
I have also lowered my hand over a hovering
Mavic 2 and it, the sensor, forced the drone to the ground i.e. it over rode landing protection, as soon as I took my hand away the drone climbed to at least the landing protection minimum, I don't remember if it went higher.
One other sneeky setting "current altitude" which can 'mess' with RTH behaviour.
Read the RTH section CAREFULLY, DJI have a habit of altering RTH behaviour for each new drone, so the
M2P may behave differently from the mavic 1.