Gotta say, if I found out that this was happening at my FBO I'd ditch
it and find a new one whether the student was me or not. No way I
want some guy with 2 hours time chasing me across the ramp because he
lost control of the plane. There's something to be said for taxi
practice WITH an instructor but doing it solo... even to the fuel pump
before someone is signed off to solo is just dangerous.