I have found that they worked really well when it comes to getting better tenants and better rents, and having less hassle, less headaches, and then getting a higher sales price; without paying closing costs or realtor fees.

A lot of your returns come at the time of sale. 

For the son to qualify for the $250k exclusion, I believe he would most likely need to meet the ownership and use test, meaning he needs to own and live in the home as his primary residence for at least two of the last five years before the sale.

I've argued for this and the powers-that-be do have a good argument that they are still active just in other ways, how to cover labor and actions during that, etc..

It’s unnecessary and potentially problematic to add the ex-partner to the title before the sale.

There is not a taxable event to you on the sale.

By negotiating a significant discount, buyers can secure great deals while meeting the seller's urgent need to close the sale.

For those who’ve structured wraparound mortgages, what strategies have you used to avoid triggering the due-on-sale clause?

The goal is to slowly build a real estate portfolio and get to a point that I can eventually sale my business. 

Q2 is most important: If the mortgaage is upside down, it would have to be an approved short sale and that could take a very long time to rectify.