It sounds like you'll have well over $100K into it, between down payment and closing costs - is that accurate?

The rentals are paying the holding costs on it so far (taxes and insurance are high in this market).

Cap rates, location, and understanding the cost per door alongside your mechanicals and capex is going to be key when buying multi-family. 

I will have access to ~1M in cash for down payment and closing costs (I would also have reserves, separate from this capital).

Considering your goal of house hacking a duplex, while FHA loans are common for first-timers, there are alternative financing options to explore:Conventional Loans: Need more credit and down payment, but offer flexibility. 203K Loans: Ideal for fixer-upper duplexes, bundling purchase and renovation costs.VA Loans: Great for vets—no down payment, competitive rates, and no mortgage insurance.Portfolio Loans: Private lenders, good for unconventional income or credit histories.Hard Money Loans: Quick, high-interest, good for investments or major renovations.With $30,000, mix it up—use it for a down payment, maybe pair with a conventional or FHA loan.

The recording can typically be executed within 2-4 weeks of closing with the title company, there is a typically a cost associated with the recording.Any similar experiences or cautionary tales regarding the use of an LLC for an investment property or STR acquisition?

You'll also want to make sure that your rental will be competitive for the area you're in regarding the rental price and quality of materials in the property.

You can trying getting a HELOC on one of your property (best on primary) then you open a line of credit to use those funds to cover your rehab costs.

Send a return receipt certified letter notifying the tenant of the issue and if applicable their cost of the repairs.

In general ADUs in single family zoned areas add less value than the hands off cost to add the ADU.