>>13551489It's still not considered a stage as far as I know, not even by Virgin Orbit or the other air-launch-to-orbit launching companies like Northrop Grumman which now makes Pegasus. Height isn't enough, otherwise launching on a mountain would be a stage.
>the main reason for using it is flexibility in launch locationThat's the only reason which includes the access to lower inclinations with no extra delta-v otherwise it's pretty much worthless.
