Again, the BiggerPockets store has some books on this topic, or you can learn about it by watching podcasts, reading blogs, and interacting on the forum.

He puts out new Youtube videos regularly and, judging by the comments, his followers are still falling for it!

Pretty much any regular bank / lender is going to require themselves to be in first position on all the properties... so I don't think a HELOC type solution is going to work across multiple properties with multiple lenders.  

I appreciate the suggestion to check out Tim Delaney’s posts - I'll definitely do that.FYI - I’m also a regular listener and fan of your BiggerPockets Money podcast, so it’s great to connect with the community here.

They do a good job of regularly releasing episodes and they frequently talk about starting out with their initial capital pool and growing their business. 

STR's don't create real estate value they are a business  I have a dozen and am building 2 more this year so I like the business model and I have over 100 regular rentals.   

Sunnyvale in Bay Area for example, places a owner occupied deed restriction when approving JADU permit (not for regular ADU though).“ Owner Occupancy Required/Deed Restriction (JADU Only): The property owner must live in either the JADU or the primary dwelling.

The ceiling can be durock or greenboard, never regular drywall. 

Having people who know the market and can help you manage the project or property is crucial to project success, especially if you can't be there regularly to handle things that will come up.

Again, the BiggerPockets store has some books on this topic, or you can learn about it by watching podcasts, reading blogs, and interacting on the forum.