He can roll it into a SDIRA and can invest from there, though there are complications in doing so.

The home warranty companies have obviously studied this in coming up with their own business models.Home warranties are a great way to sell an old or complicated single-family to a retail homebuyer.

They see anything else as "complicated". 

I'd prefer some degree less and snow...can't wait (it's like when you're a child and wake up and see the white landscape...I feel that way every year :D ) The garden parties are a little bit complicated this year...but hopefully next year things get normal again and we can have more people around and enjoy the reunions again.Yeah, technology and science is evolving from day to day and the TV's from "yesterday" can't compare with the new ones, the differences are really big.

And it is a little more complicated than that and you need to know other wholistic rules to conclude. 

Is it worth the cost, the complications and the knowledge you need to acquire though?

It only gets complicated if they happen to return a declaration claiming they are affected by COVID-19 and have an inability to pay. 

It's way too complicated and convoluted.

So yes, it DOES work, but a bit more complicated than what some make it out to be. 

If you speculate refinancing and doing 1031 exchanges that makes the analysis more complicated.