I can't really tell if the cut took yet but it is looking strong!
How old is it now?
You can always try to transplant into soil without the MG if you have any.
It is looking strong enough to put into 12/12 if you want to.
Do you have a pic of your grow set up? I don't remember, sorry.
Outside is probably a better place than that rig you have right now (what are the temps in the box?). It will grow a little slower and stretch a bit but it should be ok as long as temps are fine.
It looks like it is over watered though.