With this airplane in msfs2024: Patey Aviation Draco X
I flew at 300 000 feet altitude and I can still climb, steer, go down or up. Engine works fine.
Max altitude says 30 000 feet. But on 40 000 feet altitude I can also still climb and steer easily.
Can this plane actually do this? Or is it a bug or not yet fully developed aircraft? Or is the physics in msfs 2024 still in development?
Great! I’ll be able to go for a ride in space with my Draco and see the Earth from very high altitude. I have to hurry before this is fixed. 
It sounds like a bug to me. I’d suggest creating a new topic in the Bug Reporting Hub and let the dev teams figure out if it is a core-code / Draco-X or physics issue.
A rather HIGH LEVEL bug too… 
I tried to duplicate this just for fun, and couldn’t. Had trouble climbing above 53,000.
I tried last winter, barely could get it to little bit over 50 000 feet.
Typo in OP’s post and they meant 30,000 feet?
I used slew mode, is that why the aircraft didn’t break?
Parachute also seems to climb at 90 thousand altitude no issues.
Video example