I've read this discussion with interest. Going back to your original question, the reason the Trinity study focuses on traditional stocks and bonds is because that was the purpose of the study. They were not studying real estate, or private loans, or other investment vehicles. The premise of the study was to identify a safe withdrawal rate for stock and bond investments. They also further specified a stock/bond ratio, and a 30 year time horizon.
The reason for the 4% SWR was due to a sequence of returns risk. It is quite possible to use a higher withdrawal rate, and most of the time you'd be okay. But if the market dropped right after retirement, and stayed down for a while, your traditional stock/bond portfolio would fail (you'd run out of money.) Thus, they settled on 4% SWR. Further testing since then has let other people to prefer an even lower SWR, such as 3% or 2.5%. On the MMM forums, early retirees are looking at 40 or 50 year time horizons, so that's another reason to be conservative.
In other words, the 4% SWR isn't set in stone, and many people choose a different rate.
You're trying to go the other way. Instead of a more conservative rate, you're trying to find a more aggressive level. That can work -- just don't base your results on the Trinity study (which was limited to stocks/bonds).
Someone once pointed out that you can use a much higher SWR using real estate. It was noted that during the 2008 financial crisis, that rents stayed stable even as house values crashed. In other words, if you owned real estate, it didn't matter as much what the market did. You could still weather the crisis (especially if you had no debt). The money you get out of rental property isn't coming out of your equity. You were only in trouble if you had to sell.
I am not a real estate person, so I can't address how true that is. I can believe that while stock markets are (mostly) efficient, real estate is less efficient. There is room to make money actively investing there.
I also can't speak to crowdfunding. I don't know that topic, or what the risk characteristics are. Nobody actually cares what SWR any individual picks. It's up to you as to what you're comfortable with, and it's up to you how you approach early retirement (or even if that's your goal.)
Lastly, if you only want to talk to accredited investors, you might want to ask the question on the bogleheads forum. It seems like every other person there is a millionaire or will soon be. Their philosophy is also more aligned with yours. While they espouse living below your means, MMM is at a different level of frugality than a typical boglehead.