This affordability factor, combined with the potential for long-term appreciation and steady rental income, makes older low-rise condos a compelling investment choice for savvy investors looking to diversify their portfolio in Miami's real estate landscape.BUILD EQUITY – Investing in older low-rise condos also allows investors to capitalize on potential renovation opportunities.

Then, in order to generate more income and also move closer to work, I decided to sell my house and move into a 4 unit MF in a city where I live in 1 unit.

Not sure about loan LLC situation but if your investment properties are with you LLC then you can use that to count as income.

However, I am better, at relatively and enough for myself, investing in dividend growth and income. 

"Where is the cash coming from if the asset isn't generating any income?"

The method you mentioned (BRRRR) is operating on the calculated risk that the property's value will appreciate enough (after renovations) that you can pull out a comfortable amount of cash and use towards your next purchase... all while the potential rental income from the newly updated property going towards paying down your loan balance. 

Prices are high vis-a-vis incomes unless you're a Bay Area commuter.

If your all-in cost to build for below market value and you are able to place quality tenants, then you should be able to leverage the completed project in a way that allows you to pull out some of your initial investment tax deferred to fund future investments while keeping the rental income and future appreciation.I am a CPA by day and advise many developers on tax strategies.

It also provides the income or arbitrage without the risk or cost to furnish.

And you lose depreciation and deducting expenses against income.