Focus on the big moves: security, renovations, and cutting dead weight. 

He took a 401(k) loan to fund the down payment on a four-unit building in a rapidly appreciating neighborhood.

If the market is appreciating rapidly, I'm with you—equity growth takes the lead.

The foundation was already approved, permitted and finaled years ago for a 3400 sf house, and its solid and I won't be building directly on the overhang edge; but rather back away from the edge a few feet to prevent any load issues all the weight will be on the longer sides of the existing footing.

This area might grow even more rapidly if we get space command back.

Ideally it should still cash flow solidly but may not appreciate quite as rapidly as the bigger market.

Long-term buy-and-hold rentals in stable neighborhoods, prioritizing consistent cash flow and responsible management over rapid appreciation.

I too appreciated your response, so your recommendation will hold a lot of weight. 

Once you've identified what's important and what ratios to look for to evaluate a property, all future deals should be weighted against those "good" ratios/numbers - and periodically adjust to suit your goals.

It does however give you a degree of independence to choose what you want to do.As your portfolio grows you'll also feel the weight of future capex responsibility more, which ironically points you to growing more cash flow through more real estate.The other issue is that you are chasing a moving goalpost.