Id like to see yours matt.
I'll chime in here with a couple things. I think its pretty important to mention that these trees rely on their mychorrhizae, so inoculating one way or another I believe is an important aspect of collection. also, they prefer a more acid soil, and it seems they like a finer soil as well. I collected a seeding and a chopped stump last season. Seedling was just dug out with the rootball in tact and planted in my garden bed, full sun and pretty much full wind. leaves were ugly, but the tree lives and has some nice buds on it right now. The stump chopped one went in a 5 gal bucket with pumice, bark, turface and tree tone as the soil mix. it sat for most of summer, but I noticed the chop point to have a healed over portion and eventually buds came out real late in summer, the buds on it are smaller than the buds of the one in my garden bed, but appear to be alive and well. one other thing, I've actually seen many bonsai size beech with low useful branching, just seems they usually lack taper, and movement, but offer a decent nebari and useful branches.. ones with taper, movement, nebari, seem to lack low branching. I think with proper branching, the species can be adapted to a straighter trunk style. heres a couple that dont offer much at first glace, but I think could be adapted to bonsai, with a lot of time an effort. I'll likely just leave them in the woods and watch them react to the chops. I've also found many that look like these, which are root suckers, I've separated 2 or 3 from the main roots and left them, and have found them to be still alive after that.