Due diligence for absentee owner franchises

I'm looking into this as well. My understanding so far is that the additional step is really understanding the relationship between the franchisor and the franchisee. Starting with reading FDD for the particular franchisor, but more importantly doing validation calls with other franchisees. If it's an established franchise with good reputation, the due diligence should be relatively straight forward as the franchisor usually does good job of collecting important financial and operational data and all those will be shared. If it's a relatively small franchise, I would do a ton of research on that franchisor to make sure the business model is sound and their franchisees have been doing well. I would also hire a lawyer who specialize in franchise businesses for the legal part of the due diligence.