Unless I misread the info............

PEX-Al-PEX is ok for air but................. is regular PEX ok for air
?

I've seen it used in lots of labs for gas/air but at what pressures I
do not know.

The issue with PVC & CPVC is aging, brittle failure & the generation of
shards. My experience with PE is yielding failure, no frags.

I am not completely sure about the use of PEX for air & would suggest
further investigation before the OP does his installation.

PEX is not UV resistant & must not be exposed to sunlight.

cheers
Bob