I don't know how I missed this thread until now. Milling & working with thick slabs is pretty cool. I have no bandsaw mill or a rig like you have, but I've built things out of slab hardwood. I have a few local sawmills nearby. There's nothing quite like working with big, heavy wood. Is hackberry a fairly hard wood? I have no experience with it. Grain & color in your pics look good.
I have 4 live edge, spalted maple ovals, cut on the diagonal from a maple trunk. Numerous "ghosts" are showing in them, and I have them finished with 7 coats of clear Armor Seal. All they need are legs to make some smaller, beautiful tables.
Do you just sell the slabs, or do you make things out of them?