You need a third-party note buyer.Yes, these note buyers will be looking for a discount, but that's the cost of converting an income stream back into cash ahead of the agreed payment schedule.

But a good portion, even now, are converting and the clients are very happy.

This could be a rental, but I really think that the real value is in converting it into a TIC.

I've seen conflicting reports that says if you use any portion of the advance for COVID related expenditures it converts the entire amount into a grant, not needing to pay back anything.

@Berridge Thomas To tack onto what @Dave Foster is saying if you converted to Roth... you now have stepped up your basis and created another option where you can pull your basis tax free (because you already paid the taxes). 

I'm considering converting one of my SFH (4bd/1bth) rentals into a rent-by-the-room situation.

She stated that she converted to gas back in 1984 and filled the tanks with sand but doesn't have the documentation. 

You'll convert one months rent worth into a security deposit...This is a nutshell of the scenairos, issues, in play with rent to own to folks you don;t know. 

So rather than looking for an RE with a garage to convert, you likely would be better off looking for an RE with an existing ADU.

My fiancee and I converted our traditional (me) and roth (him) IRAs into self directed retirement funds (these were from our old W2 jobs/invested in stocks/mutual funds) We now both work for ourselves, so were able to roll over to a SOLO 401k and invest in real estate.