You're going to end up paying a lot more interest on a heloc than a 2nd mortgage, if you intend on holding that debt for more than a couple years. 

Couple is splitting up and one is wanting to stay. 

Painting, for instance- an amatuer could take their time and paint a house over the course of a couple weeks and do a great job, but a professional crew could do the entire job in a day. 

A couple only lasted 2-3 years before closing.

If you were renting to an only a couple as a long term tenant and they beat each other up (domestic violence) your liability is minimal.  

I then modify those numbers based on the buyer's preferred down payment/return hurdles.

Reason being, I hired a property management company (just now) and they're wonderful, they start officially in a couple days. 

Quote from @Collin Luckett: I have a couple houses I’d like to put under contract as fix and flips and would like to you private money lenders to help fund.

I'd simply explain they can use Zelle until the renewal, then the portal will be the preferred method.

Happy to DM you a couple of platforms I have come across that may be complimentary to but would not replace the underwriting work.