May I ask a (probably) silly question ?
Doesn't the B747 have the same characteristics ? If not, isn't it over-powered and hence less economical ?
A couple of years ago I departed on a SAS A340 CPH-ORD. I would swear that as we exited the CTR, we were in G airspace for around 30 seconds, actually exactly at a VFR reporting / holding point where I've been many times at 1400 feet in a Piper 28.