Businesses in my opinion can be the best because on apartment units for instance rent can only within reason go to "market," before no one will rent any more of your units but in business you can create value like apple and people will pay a higher price for your product (a premium) and your magnitude and velocity is "limitless."

When you have self-directed plan you have virtually limitless investment options - real estate, private lending, tax liens, precious metals, real estate notes, etc.

I understand that the options are almost limitless to non-licensed investor, but I’m concerned with a licensed agent/investor situation in regarding to REI options.

Has anyone heard of Limitless Turnkey?  

I love that earning potential is limitless.

The opportunities are almost limitless.

So to encourage multifamily real estate owners to undertake necessary capital spending, the government permits them to take a depreciation deduction against current income equal to 1/27.5 (or 3.6%) of the building’s value at purchase each year.In other words, even though buildings practically have a limitless useful life, the government allows you to treat a multifamily property as if the property will become obsolete in only 27.5 years.

There are legitimate reasons for taking this route, like if you are a high-earner and just need to "park" cash in a safe investment in exchange for lower returns or perhaps as a hedge against vacancy, rental market fluctuations as the rental demand in these areas is limitless even in challenging economic environments. 

The possibilities are limitless.

There is a solution to everything and limitless possibilities to what you can accomplish :)