I was pre-approved for a conventional mortgage with a 3 % down payment 2.75 Interest Rate.

9) adding multiple ADUs or adding an ADU to a quad looses F/F conventional financing.

Conventional would work too, but you would have to wait at least a year on seasoning, DSCR is only 6 months.

I'm trying to automate and digitize more processes of managing long term and shortterm rentals. 

For example, in Mexico, you can put less than 40-60% down, interest rates are in the single digits and you can get 20- to 30-year mortgages (and you can't get anything shorter actually) and the right areas would fit within @Richard Foltys' criteria.

This will also allow you to rehab the property at your own pace assuming you buy it using a conventional loan.

My condo is an HOA that is suddenly non-warrantable for conventional financing.

I read newspapers (Digital) in the markets I am interested in.

Thanks, HELOCs the way you want them probably structured as a DSCR do not really exist to the best of my knowledge, you can do an investment loan heloc for a super high cost, but you will be subject to a traditional conventional underwrite.

Analyze cash flow, potential vacancy rates, and maintenance costs before making a decision.Secure FinancingTake advantage of owner-occupied loans such as FHA, VA, or conventional loans, which often have lower down payment requirements.