When the kart is blocked on a kerb, I need to go back to pits as pushing the kart is not possible to unlock it.
Is-it possible to get out of the kart, lift it and push it at the same time?
If not possible, this post should be moved to suggestions / whish list subject.
try use keys L and O then you can move the kart.
The slow speed works a lot better than previous versions but I have the same suggestion. In real world no matters how the kart is, you can always push it and go back to the track, even if it is up side down or in hanged in a tree :D