I have a side quest to root plums as just a badass way to propagate them

I have a side quest to root plums as just a badass way to propagate them. benefits could be a healthier, longer lived tree. the last toka trees on their own roots were last century when Hansen was making crosses. I've been able to root it with some high degree of initial success, but plums get messed up and don't harden off the first winter when you do this. Trying these large plugs, so far growth has resumed (a good sign) and by october if the leaves are still green I'll move them into the greenhouse to try an extended fall season to enter dormancy, then pack in the root cellar. maybe also a low N fertilizer. the last time I tried this was in ground and bare root, hoping this run works better, trying to find the right protocol, other plums can also root.