When pulling a deep vacuum on a 410A system at what point will the POE oil vaporize?

I know POE does not give up moisture like mineral oil and some suggest a system should hold 500 microns with pump valved out for 5 minutes. Others say to pull down to 200 and hold at or below 500.

My question is at what point is the vacuum vaporizing the oil? There is no need to vaporize perfectly good oil. Is it possible to harm the structure of the oil by going too low?

If time is not an issue and perfection is the goal, what would the ideal vacuum be?

With the cond unit service valves closed I have pulled the line set and evaporator until they would hold below 50 microns for 10 minutes. After opening to service valves back up what would the perfection goal be?

This would all be in reference to a system that has been recovered and opened for service such as a TEV replacement and the cond unit has had nitrogen in it with the service valves closed. Not a burnout or any other major failure.

Is there such thing as too low?