I am in an interesting situation where I am in need of money to finish renovations on my primary residence.

Used a HELOC on a primary, and was sure that even with that additional debt-service, there was + cash flow.

No lawsuit against you can deny the fact of bounced checks. 

Used a HELOC on a primary, and was sure that even with that additional debt-service, there was + cash flow.

Start with your primary, rent out any spare bedrooms "house hack"Use that to practice upgrades, kitchen, bathroom, curb appeal... etcNow you have experience as a landlord and flipper, use that to buy a distressed propertyAdd 40% equity to the property through home makeover, refinance into a low cost mortgageNow you are cashflowing a healthy margin on a second property, use that to build equity over time, cashout later and buy your duplex/quad.If it's going to take you 10 years to save up a down payment for a small apartment building, yeah it makes more sense to start growing your portfolio with cheap SFR flips instead.Every market is different, every borrower is different, every property is different, it would be ill-advised to recommend anything without recognizing the individual's nuanced goals and objectives with their next acquisition.

My primary residence is in a trust.  

We’re debating whether to sell our first primary residence or keep it as a rental.

Living in one unit and renting out the other helps you scale quickly because you need a lower down payment for a primary residence. 

If married you can exclude $250,000 each in capital gains if your primary residence.  

Balancing rental income, appreciation potential, and location can provide a primary home and a long-term investment portfolio.Good luck!