If it were my tree, and from what I can see in those photos, I'd keep it windswept as I can't see how you'd get the branch structure right for a root over rock. What I'd do is get some major movement into the top two branches and then once they set, jin them, and grow the lower branches into nice sparse pads. I think it will make a better windswept tree.
Either way, that's just an opinion, so whatever you do, have fun and enjoy the process. Good thing that you caught the roots/growing medium in time. A winter in a potting mix you describe
coulda been the end of it! Cheers,
Andrew
