Or turning your current residence into a rental and buying another primary and living in it until you can rent it to cash flow. 

The lighting is a little dark in the picture but this will be a lovely/bright kitchen and living room for our next resident.

My current asset allocation based on age and risk tolerance not counting my primary residence is 70% stocks, 20% RE, 10% cash/bond type vehicles. 

If you're not resident in Japan, you can't borrow from Japanese banks, and so that's out the window. 

In this case my plan is to use a HELOC on my primary residence to purchase the property in Puerto Rico.

Yes, the intention is to build a primary residence for my family to move into. 

I have not had any experience with Easy Street Capital, but David Lichten resides in Gardiner, Maine and I have done many deals with him. https://kennebecrealtycapital.com/It's great to have options and compare, plus he is local! 

Padsplit residents can cause problems with neighbors and other residents because many have substance abuse and/or criminal histories. 

I buy homes as a primary residence with 5% down and move into them keeping my previous as a rental and the area that I live doesn't have new builds that would work for us, otherwise I would buy a new build. 

Since your lender requires prior experience building and selling/refinancing a single-family residence (SFR) on your own property, you may need to adjust your approach.