mhhh should be the opposite around not third person on foot but while flying

Because disabling first person using the game option disables it when you are on foot too.
This lets still lets you go in to third person when out of a cockpit.

While still slightly (very XD) cheaty, being able to go in to third person when not seated is not likely to affect ship designs, operation, and crewing. You would still need someone to go out to where your connector is, or look out a window, etc

Why not just disable first person using the game option?