I currently have 7 rentals units ( two three unit properties, an investment condo and a garage space) Currently I accept many forms of payment including Zelle, Venmo and paper checks.

I remember a buddy who once represented a client in the Santa Cruz Mountains.. this client turned an old barn into a shared art studio and invited local artists to rent the space, which ended up boosting inccome in ways they never imagined.The Redwood market can be tricky because of environmental restrictions, zoning quirks, and limited inventory.

A common theme amongst those who are successful scaling a real estate portfolio and affiliate real estate businesses is organization skills that allow for systems to be implemented.

How confident are you that you'll be able to pick up something good in the 2-4 unit space? 

I feel like it's a space where great operators can really clean up, since the bar is set really low, in my experience at least.

Tried other things but can't make anything better since it gives me space, allows me to prioritize and delegate, and is practically free.

MTR attracts a lot of traveling medical professionals and WFH individuals who need a quiet space during the day, which may not be compatible with families living in the attached LTR.

Not really common in the 1-4 unit residential space. 

In the current market, it's pretty much impossible to have any positive cash flow in the 2-4 unit space with long term rentals, unless you're putting ~40-50% down, not only focused on the cash flow per se, but rather simply not being in the negative.

If it's in a shared space like a basement that's one thing but if it's in an occupied unit, that is something that may not be allowed in your jurisdiction.