So in order to get private funding for my next investment property I needed to register an LLC as they don’t lend directly to individuals.  

A lender is not going to be eager to loan on a property to an individual who isn't on deed (one of the complications of sub 2 dealing with title insurance not IRS). 

Or info on any effects of changing ownership of the STR from joint to individual in the case of a divorce? 

Individually owned2.

We try to rent together until 6 weeks before vacancy at a price that is higher than the sum of the 2 units individually.  

You definitely want a "like-minded" individual but you don't want that person to do the same tasks as you or its all just a big waste of time.

Again, I would love to connect with some individuals who have experienced this process before or know a lot about it. 

I am not a PM or attorney, however I have seen other owners just do individual leases for each tenant specifying the room and terms. 

As the impacts of climate change become increasingly evident, more individuals are likely to incorporate considerations of air quality and other disaster risks into their choices when selecting a place to live. 

If a cash out refinance, many lenders will allow the cash out to satisfy the reserves requirement.DSCR lenders generally let you vest either individually or as an LLC.