The only other advice that I would give is if your primary motivation is to save on taxes, don't do it.

I have a primary home and a rental near Portland, OR.

Even in HCOL areas, adding an ADU typically does not make sense because developing a single small unit is the most expensive residential development that exists.Adding an ADU is a lot of work (probably more than a brrrr but with worse return), has poor financing options, typically adds less value than the cost of the addition, and detracts something from the primary structure even if it is just yard and privacy.Good luck 

This allows you to access funds while keeping your existing mortgages intact.Second Mortgage: Explore lenders who offer second-position loans on investment properties, though rates will be higher.Cash-Out HELOC : While traditional banks often restrict HELOCs on non-owner-occupied properties, some portfolio or private lenders may offer HELOCs for investors.With $15-20K in liquid funds, look for deals where you can negotiate terms:Seller Financing: Negotiate lower down payments or interest-only periods.Subject-To Financing: Assume the seller’s existing mortgage while covering the down payment.Lease-to-Own: Lock in the purchase price while using rental income to build equity.

Right now, it is incredibly tough to make even a few hundred a month with traditional strategies.

The challenge, as you’ve discovered, is that traditional HELOC lenders typically want the property titled in a personal name rather than an LLC.

On the other hand, if you're aiming for long-term rental properties, getting prequalified with a lender specializing in traditional loans or DSCR (Debt Service Coverage Ratio) loans is key.

I would not be living in any of the units as I already have primary residence in town.

That level of diligence isn't possible with human effort or even traditional data processing techniques.I would like to expand to investors in the future but this technology is very new. got it also commerical Brokers I suspect would be a target for you.. 

When I return to the country after my Au Pair contract ends, I hope to live in the property as my primary residence and house-hack as well.I understand that investing remotely makes things more challenging, but I am also ready to be uncomfortable and challenge myself in this journey as I know it is 100% possible.