My 20 bushels turned into 15 gallons of juice. I didn’t count the windfalls, which all went into sauce.
Of the 3 trees I originally grafted I now have 1. I believe the bark splitting I reported was due to late season growth that wasn’t hardened off before winter. The final tree I have is not at all vigorous even on B.118. It seems to me this is a Z5 apple as suggested in what I’ve read. I’ll probably graft 2 additional trees to see how they do, but I don’t hold out much hope this tree will be productive in Z4a.
None of mine have ever maxed out on size. Even the big, ancient original one on seedling stock was happy to go bigger forever. All of my grafts (mm111, mm106, g890, g41) have grown really prolifically.
I can’t comment on cold hardiness, I just get explosive growth on everything in z9.