Are forgivable 2nd mortgage down payment assistance programs considered QM's subject to TRID? If so, would they be a standard QM?

You are mixing apples and oranges. I am not sure what you mean by considered QMs. How you underwrite the forgivable loan determines QM status. Are they subject to TRID, yes. They are a consumer loan secured by real property. Most lenders disclose the loan based on the underlying legal obligation that exists. The fact that the monthly payments are waived if they continue to meet the conditions would be treated as a subsequent event.