Using a HELOC for the down payment on the second home might be an option, but lenders may require you to wait a few months post-closing on the multi-family before approving new loans.The BRRRR-style approach could work if you can renovate and refinance quickly, but make sure the timeline aligns with your lender’s requirements.

A partnership requires three things to be successful - Experience, Capital and Time.It looks like you have the capital and experience but maybe not the time.I have my doubts about this working if you have a friend who has weak credit and a limited cash flow.

A big reason is the OO requirement to rent the JADU as its own unit,good luck

If you sell your only overachiever to go with a more leveraged position, you could have 2-3 properties that may cover themselves or even provide a little profit, but when the rental markets shift (and they do), now you have 2-3 properties that all require you to supplement for their shortages. 

The vast majority of properties at their available prices will not meet this requirement.  

The last few years have been great for investors/homebuyers who bought pre-con, but looking back to the few years after the 2014/15 boom, this wasn't the case, where many had actually committed to buying a property that wasn't quite worth what they signed up for closer to closing because the appraisal weren't matching the contract price, requiring a cash top-up.

As Jay mentioned they must be NMLS licensed if owner occupant of in several states even commercial needs licensing.The NMLS is like the database, each state has a division of banking that oversees lending requirements then you also on the federal level have CFPB as well as consumer protection laws.I want to add that I believe yesterday the CFPB is undergoing changes, but if it goes away that does not mean that many of the laws in place especially consumer protection laws would go away. 

I'm being required to pay another application fee and then $600 application fee to hopefully get this approved by the Board to allow me to continue running the STR that they approved 6+ months ago. 

Quote from @Abhijit Roy choudhury: Financial Crime enforcement Network, requires reporting of Beneficial Ownership Information filing by 01/01/2025.Does this apply to us, Rental LLC owners.

Managing self-employment income requires tracking eligible deductions like business expenses, home office use, and retirement contributions.