The Housing Wire article chart shows how FHA and VA loan delinquencies are approaching really high historical levels, close to that of the housing crash.We are still at historic lows for conventional loans.

and even then the return will be fairly low based on the risk you're taking on. 

Fees are really low too. 

We also have relatively low expenses (personal expenses, mortgage/escrow on other rental property, and escrow on current property) that are around ~$120k/year.

We also have many unique buyer incentives where an investor can get up to a 10% price reduction to come into immediate equity, or get that 10% as a cash back at closing to reduce your down payment and increase your ROI, or buy rates down into the low 4s on 30yr loans to maximize cash flow.

Biggest lesson would be to have refinanced when interest rates were low and locked in a fixed rate for longer terms without a balloon payment!

The owner occupant rate is super low compared to many states but as a rental it goes up alot.  

Have some diversity, C areas with low entry and high cash flow, the majority should be B areas with stable income, appreciation, tenants. 

The first option will give you continuous headaches with a certain likelihood that the behavior may get worse (not paying at all and more damage).

Your primary has an incredibly low interest rate, and your rental (I hope) is getting positive CF, which means your tenant is paying it off for you.