These are very different than Subject-To, as the loan actually transfers to your son's name, and off the seller's name. 

I know many landlords set a credit score threshold around 580-600 for Section 8 tenants since the program provides a rental guarantee.

It would/could be only 15% capital gains tax and yes you could/would deduct all selling costs including commissions and transfer taxes.

So before I transfer ownership back and start a seasoning period, I thought I would ask if there were any solutions I am not finding.  

There are some that provide coverage but of course the premiums and higher. 

You could convert them to a DSCR loan but then transfer them to a LLCWhat we have done is save for down payments and renovation costs, - buy properties that need work rehab them and then refinance them out making sure it meets our dti.

@Cosmo DePinto, I can provide further insight on behalf of my market.

Unfortunately, I think you should eat the cost on this.If you have a door that can lock, you should provide the key.

:We use the cheapest ones that they provide at Lowe's, our handyman installs.

It is hard to beat the appreciation, cashflow, tax benefit and the hedge it provides against inflation.