FICO 640 + DTI 50% or better.

It's not just about maintaining the property; it's about enhancing its value and providing a better living experience for tenants.

I often wonder if it would have been better to have started with a single family as our first, to learn the ropes, and then graduated to the 4-plex model. 

You should be able to learn from them so this makes you a better investor. 

It's better to get a duplex in a good part of town compared to a 4 unit in a bad part of town. 

The percent returns are typically not much better, its just you make more money on a $10M building than you do a $100,000 asset. 

My goals are grand, ambitious, and future proof.I plan to build affordable homes in a way that is self sustaining, and desired by many.I plan to invest into Single family homes, and multi family homes to get the individuals who live in them a better life.I live in Utah, so the market is not the best.

Constructing an IRR timeline on both options using the timeframe you decide on will help you visualize the better yielding investment.

From what you wrote, I don't think you have much guidance because you should be able to do better than that in your area.

is it better to pay down more on the above SFR and bring down the DTI ratio and then leverage the SFR and use that amount to buy another townhome?