Result of lots of searching on net is that pre-checkout hook in git is not implemented yet. The reason can be: There is no practical use. I do have a case It can be achieved by any other means. Please tell me how? Its too difficult to implement. I don't think this is a valid reason

Thinking it might be about performance is plain wrong for at least two reasons. Please read this info about the performance aspect

By the same token, marketing or political incentives often push design idioms