Helping a friend with a down payment + 1031 Exchange

[Max K.]

A friend of mine is purchasing a single family property in a desirable suburb of Boston, MA with considerable room for equity growth. He's only putting 5% down and will be paying PMI as a result.

On the other hand, I'm in the process of selling a flip and should have my profits distributed before my friend closes on his home.

My thought is that I may be able to use a 1031 Exchange to put the money towards his purchase as an LP and help him get to 20% so that he can avoid PMI.

There's also a considerable amount of rehab to be done, so he may be interested in having someone else with "skin in the game" who is incentivized to help with the renovations. 

Thoughts? Does anyone have experience working in such a partnership? What kinds of pros and cons may exists? What might I be missing?

It sounds like a win-win to me.... Interested to hear what people have to say.