I’m on the west coast so pools are often a selling point and can charge more for this feature.

This will trigger tax consequences!

If so, why not partner with someone else that can help you fund the deal, either 100% or have your money partner fund 20% and a commercial bank fund 80% then flip it and split the profits w/ your money partner at whatever split you all think is most fair? 

It's still relevant, but not tremendously useful for residential properties like this which are valued by comparable sales.

Use HML to fund renovations• During this time, pay holding costs OOP (including P&I with PMI), any left over money can be used to build up next savings fund5.

Would this be a letter of intent or promissory note?

Happy to discuss the financing aspect of this if you'd like.

tell me please- what is this website that you using? 

I'm scouring my history and can't seem to find the podcast where they talked about this. 

I can't connect you with IRA/401k lenders, but certainly you can educate folks on this concept.