While the G91 does start on the runway a number of its systems require interaction before take-off in order to fly properly.
Haven’t checked with the G91 but with the MB-339 fuel mix control binding on my hotas does have an effect on fuel/throttle control. - it seems to act as a throttle fuel cut off if I left it at 0% this might be the same in the G91?
The effect in the MB-339 has been the same though…scrambling to fault find the issue and restart engine while losing altitude. (actually quite fun)
This won’t be true if you simply ran out of fuel though…