I’m not sure why this is directed at me. I have no affiliation with DEVONtechnologies, I’m just a fellow user trying to be helpful.
I’ve migrated seats a couple of times, but I’ve never run into that limitation, so I wasn’t aware. I don’t know if the reason is technical or if it’s a measure to prevent abuse—but I do have a sense that this is not unique to DEVONtech at all.
The folks at DT are generally quite reasonable. I would contact support/sales and explain the situation in a friendly manner. Hopefully you can figure something out.