Primarily it is because he gets credited with "writing the book on notes" which his hardly is.

.- The whole process is simplified—no co-ownership legal headaches.I’m curious about the pros and cons of something like this.

I'd offer him his $190,000 if he will take payments at 3%, NO BALLOON, you'll make good money and get tax write offs. 

Like you, I’m diving into books and podcasts, but I also believe there’s immense value in learning alongside others and gaining hands-on experience.I’m in the process of connecting with like-minded individuals to create a community of new investors who are eager to learn, share knowledge, and even collaborate on deals.

For the BRRRR process I plan on using a hard money lender for the rehab process for the SFH's but what I'm not sure of is, should I purchase a duplex and rent one unit out and live in the other or should I just rent for now, not purchase a duplex and just purchase a SFH with cash and start BRRRR'n immediately?

If, through the process of renovating the property, the market shifts, do you have an alternate plan for the property, whether it be to live in it until the market improves, or convert it to a rental property, etc. 

I know the process from beginning to end and documented this thoroughly.

Mark, I am in the process of completing a HELOC with Wells Fargo.

But what is really important is that you understand the terms of the loan, including the length of time and when you can expect to get the money back, how it is secured, and the process of getting it back if things don't go as planned with the investment.

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.