Pay for maintenance.

You’ve developed a moderately fast wealth accumulation strategy that’s relatively low risk, enabling you to ride out down cycles, negative cash flows, unexpected necessary expenditures, etc.  

Low cost housing is a huge motivator to change behavior and keep their housing voucher. 

Be sure to hold a hefty reserve to handle on-going maintenance, capex, taxes, and insurance.

Low appreciation may make the RoI from these assets low over long term, though they will cash flow on day 1.

Rent payments from the medical LLC are fully deductible as a business expense, while the property-owning LLC will report the rent as taxable income, which can be offset by deductions for expenses like mortgage interest, property taxes, maintenance, and depreciation.To ensure compliance, document how FMV was determined—using market comparisons, an appraisal, or similar data—and draft a formal lease agreement outlining the terms, rent amount, and responsibilities.

It isn't having paid off properties that offers security, there are still taxes, insurance, maintenance and management involved. 

I actually like them because the homeowners' association (HOA) usually covers most of the insurance, and there is very little maintenance required.

With that low interest rate, you will have paid down a lot of equity in the deal and should be able to finance with a bank.

For example, I am a little concerned about some aspects of the business cycle recovery and a potential for a double-dip so I lean toward the safest part of capital stack which is debt (or low-debt equity).