I don’t know why they call M 111 “semi dwarf”. It is supposed to grow up to 80-90 % of an full size apple tree. Meanwhile, M7, also called semi dwarf, is about 65% of a standard tree.
I am surprised that your tree in M 111 flowers this early. Mine are super dwarf rootstock already so I’ll let them fruit if they have cross pollination partners.
@BobVance, hope we can compare fruit this year.