Another person with a few million in investments (mostly liquid types like stocks, no mortgages, one paid off rental property and doesn't want to buy anymore property) is make quarterly payments to the IRS. 

But as this is my first home purchase and I’ll need some liquid cash on hand for renovations, competing against all-cash offers, plus their willingness to pay well over comparables in the area, is challenging.

That money is still "sort of liquid" and I can still cash our refi if needed3.

Along with the lender is going to want to see liquid reserves Not sure how much..

Now you have 1.2 - 1.5 million in free equity to refi as well if you ever need to but you shouldn't cause the cashflow should be more than enough to stay liquid and just keep going.

Sounds to be like "burn-out" on single family homes, I'd rather have 3 houses than 6 apartments any day (comparable properties), from just about all aspects, financing, liquidity, marketability, vacancy, insurance and time to manage, residential SFDs edge out small multi family in my book.

Fabuloso... just the multi-purpose cleaning spray?

This trend is increasingly relevant in today's MF market, posing challenges for operators with fixed debt who are looking to sell their syndicated assets and have high performing assets but now the comps crush the ability to liquidate. 

Spray can or sticky film glass frosting.

So what you need to do is break out a spray can of clear shellac.