Interesting! I don’t know the rootstock, because my local feed+hardware store orders trees for customers through wholesalers, and knowing the name of the variety is about all we get, lol.
The root area/lowest trunk got hit by borers the year they really went for my peaches, so I think it probably has a lot of peach in it at least. It’s also not dwarfing, because the tree is supposed to reach the height that catalogs always list for All-In-One (12-15ft, I believe).
The suckers are pure green with leaves shaped like an almond. It does actually get affected by drought, almond or no. It needs little water, but I do have to help it out there occasionally in summer. The leaves will wilt.