Im in a rather expensive city but future appreciation looks great still.

You're not "prohibited" from claiming bonus depreciation this year, but the resulting loss will probably be blocked and carried into the future years.

You have growth in both cashflow/passive income and future ARV/equity.

Even with future income to offset the mortgage, I would not expect a lender to underwrite a SFH as an income producing property like they would for a multifamily property. 

We are estimating we could build at least six houses for a total project value of $6.6 million.

If it's a newer company,  and projected to grow, you might consider their projected discounted cash flows to evaluate the company.

If a purchase, AirDNA projected rents for the property address with 20% expense factor.

However, the real estate investments still offer the potential for tax-deferred growth and, under certain conditions, the ability to carry forward unused passive losses to offset future passive income.The concept of depreciation and bonus depreciation is particularly advantageous in the early years of an investment, allowing for significant upfront deductions.

I keep hearing that 2 or 3 BR properties rent out much better than 4 BR, but this in contrast to airdna and BNBCalc at least on projected revenue. 

When reviewing the cash flow of properties, you discovered the cash flow was not feasible for a property, you could consider a 1031 Exchange to sell the property and replace it with a new property in the most tax efficient manner.Review profit margins and cash flow for each of your properties.Is the cash flow of each property still as projected when you purchased the property?