That may be the case. I bought two AU buck IIIs and two AU Buck IVs a couple years ago. The were nut grafted trees. There were 1 year old when I go them. I immediately potted them in 3 gal rootbuilder II pots and overwintered them in my unheated garage. I woke them up early and put them under lights. I eventually acclimated them to my deck. I grew them there for the summer. Rather than having a lot of vegetative growth, they had some and then directed energy to producing nuts. I got several nuts from the cross of AU Buck III and IV. I then planted them in the field in the fall after they went dormant.
I did not protect them and they got some browsing. Then the Japanese beetles hit the leaves. They ended up dropping their leaves last summer. I have since protected them, but I won't know until next spring if they just went dormant early because of the stress or they actually died.
I cold stratified the nuts and started them under lights last year. I'm hoping these seedlings do better than the nut grafted trees. I would estimate I got about 1/2 the vegetative growth from the seedlings that I typically get from Dunstan seedlings. Rather than planting them in the fall like I typically do with Dunstans, I overwintered them in my cold room. I have not yet brought them in to wake them up under lights. I probably won't wake them up early because my basement is full of apple seedlings and Allegheny chinquapins. Instead, after our last threat of frost, I'll acclimate them to my deck and grow them out this summer. I plan to plant them next fall.
That is my experience thus far with the AU Buck III and IV.
Thanks,
Jack