I actually called support last Monday. I told them perpetual history was not turned, as I suspected that to be the cause. Nothing was said at that point. They had me send in the customer's data, took the rest of the week to look at it, and then told me they only convert perpetual history.
With the inability to import into perpetual history, and perpetual history being necessary for ACA, I guess that means that if you sell some fool Sage 100 with payroll, they can only convert at year end.