I tried this a good few seasons back with mixed success. I tried four grafts onto M27 rootstock. Only one out of four was successful. However, while three failed one of those rootstocks grew a new shoot that season that looked strong and healthy so that in early autumn I also tried a chip bud graft, and that worked. So a total of two out of four. I had no previous experience so was more than happy with the results.
I have never been tempted to try again. I love apples and have nine trees divided between allotment and garden but no more room. Also it takes a couple of extra years to get an apple tree established compared with say buying a two year tree from a nursery. Us old retirees get impatient!!
With dwarfing rootstock the trees start to fruit a lot earlier than the bigger rootstocks, which is great but needs a bit of caution. Going back a few years to when I started I got four varieties on m9, with 3 two year olds and one a year younger. But as they grew and came into fruiting I got a bit lazy and treated them all the same resulting in the younger tree being allowed to fruit a bit too heavily rather early. It ended up a bit stunted and undersized. It is a lovely tree but smaller and less productive than it might have been had I been more attentive.
Wishing you success!