Have to agree with most here in that a SF-> duplex conversion needs some really specific qualities to be worth the squeeze.

https://www.biggerpockets.com/forums/12/topics/1122318-quality-turnkey-companies?

It can eat into your cash flow, but if you're earning high income from your W-2 job (I assume you are if you're buying in all cash), it makes more sense to use your time making more income versus managing maintenance requests as you scale. 

Did have high quality photos/ great listing title and description?

If we're going to just talk in hypotheticals, of course anything is probably possible anywhere but highly unlikely. 

Forget the course and put that money on a quality vacation short-term rental.  

With big benefit potential of possibly retaining "Graduated" persons who are now highly trained, proficient employees. 

What doesn’t work today may work in the future.Another challenge with the traditional BRRRR model is the resulting high debt load often isn’t fully covered by rental income, especially in today’s high-rate environment.

Completely agree with you on this; I'm not making any claims to the quality of these lenders here.

Are their listings detailed with good quality photos?