I'm in talks with a private seller to purchase vacant land.

If your land is paid for, or maybe have some equity in it, then that could also help with down payment. 

•Even if my tenant pays on time or the day before, it still doesn't land in my bank account until 6 days later, but I think that's true of all ACH payments

Conversations with a person land so much better than a message thru FF.Also it is helpful to know that most Corporate Housing companies or Insurance Agencies that are trying to find housing for their customers and reach out to you, they do finds leads on FF.  

I've had success selling the vacant land I'm picking up on Facebook Marketplace but recently it seems to have really slowed down. 

I have been investing back home for many years and have bought up many land.

Understanding zoning, and land uses has been the extent of my experience. 

It's our goal to leverage this catalyst towards creating ADUs and housing where otherwise vacant land currently sits.

My Google search landed me on this thread:).

Most can't give an honest assessment on a properties value and now you're expecting them to advise on land use & zoning?