I would estimate the daily rental rate would $3-4k and around $25k on a monthly basis.

Of course, the rate can be slightly steeper than the conventional loans where it is a full document loan, where they need to qualify you based on your income.Alternative way, is to acquire the 2nd property as an investment property with conventional, while putting 15%-25% down payment.

It's a small commercial loan for 5+ units, but also, too small to qualify (from what I understand) for fixed rate agency debt? 

Interest rate is at 4.75% and the mortgage payment is slightly less than the market rent in that area.

The 2021 cap rate at that price was 3.5% though I expect lower now with issues and current expenses.

On the other hand, refinancing would provide a fixed rate mortgage that is lower in interest and has less concerns for paying back in the short term as long as the property still cash flows.

Switch your interest rate to 8% and run both your current 5 years and after your 5 year balloon period. 

Our primary unit is still operating about 95% occupied and rates have never declined for us.

Fixed rate debt in an inflationary environment is a wonderful thing. 

Interest rate: 2.875%.