I would look at the DSCR loan as the first option.By the way, I suspect you are going to be disappointed by any refi appraisals   ADUs typically appraise poorly   JADUs can lower the property value Vs having the space as part of the primary unit.  

Some PMC's will charge a lower percentage fee, but will charge it whether tenant paying or not.

Mean while i would be building equity, and if rates do lower, or when the term ends, could refi for better rates and then maybe cash flow.My questions are:Is this too naively optimistic?

You could bring less down and possibly have a lower interest rate since you will be living there.

This was my first deal, and house hacking made the most sense because it lowered the threshold for risk in my mind.

Happy to chat...being a local GC takes out a lot of the risk of the biggest variable for most investors (unpredictable rehab costs) and also allows you to consider more options than the average investor, with your rehab costs being significantly lower.

If the loan amount you are looking for is small relative to the value of the first and the second property combined, they are very well secured on a LTV%; ask for a 1% point lower rate.If you don't want to Cross Collateralize, do you have any CD's or MM you can transfer to this bank as collateral. 

I can send you their contact info.Quick Tip - I would start with a range of offers (lower-end), that usually helps my clients get out of the analysis paralysis phase.

Find a private lender who would give you that debt for a lower amount.

Some local banks are fine with 20% down but I don't think they'll go any lower.