I know this wouldnt be useful for everyone but it would be nice to be able to make 2x2 airlocks or 3x3 ones. It would also give them a small advantage over normal doors, and make them somewhat worth the cost.
Yes please! Airlocks should be able to be any size.
To my knowledge, airlocks are already available in 3x3, as seen at sobrii station.
those are manually placed, none-functioning airlocks as far as i know, since they have been there longer than airlocks have been on the server
this could also be done with docking tubes (altough that could be somewhat problematic)