At a minimum, having viable plans in place for development will make these lots more marketable and valuable to potential builders when we have conversations. 

I recommend reaching out to the builders directly to negotiate any potential arrangements.

As someone based in San Diego, I’ve also noticed that investors eyeing California real estate tend to focus on potential future development or expansion (especially if you have the patience to navigate local regs).

EDUCATE YOURSELF - yes, it will take time, but will lead to a selection that better meets your expectations & avoids potentially costly surprises!

Quote from @Michell Chase: I am working with a hard lender on a purchase/reno and they require a builders risk policy even though 1 unit of the 3/4 will have a tenant.  

Longer tenancies mean lower turnover and vacancy costs, so two single-family homes usually generate more reliable income and higher net cash flow than a fourplex.Vacancy risk: A fourplex has four times the vacancy risk of a single-family home.

Private lenders are not affiliated with private organizations like the American Association Of Private Lenders, and they all have different risk tolerance. 

I've noticed some really extreme discrepancies between renting and potential mortgage payments which make me hesitant to buy a primary residence.My wife wants to move around 56 (not too far from the ocean), which I don't mind because it seems they have great school districts and we have young kids. 

BRRRR with a bang: If you can pull this off, the value-add potential is huge.

Property should go for a premium just on that potential.