Besides that, the kiln you are looking at is quite small. For proper temperature control etc, if I understand it correctly, you have to be at least an inch away from all sides of the kiln In most cases, how much can you anneal?
And what kind of settings will it allow? It's small, so it's going to cool off faster than larger, better insulated kilns. Silver clay and copper needs at most two segments, three if you want to stretch it out. Will this accommodate the gradual ramping up without shattering the glass? Will it allow you enough segments to ramp back down? What is the software capabilities?
I recommend a Paragon bead kiln. A shade bigger. A shade more expensive. But geared towards glass.
I don't think I'd anneal in a pile. I'd anneal in a single layer. And if you're a responsible seller, please disclose HOW you anneal. Because with the exception of certain applications, batch annealing isn't much better than knock off Chinese glass beads. If you're not selling, it's fine. Otherwise, disclose the fact.
Edit to add: boro would be one of those exceptions.
. But do disclose batch annealing for soft glass.