I believe that an incremental rent increase is the best way to go.

When you factor in the cost of the hypothecation debt and the taxation on the resulting income from reinvesting that money in something else, you would need to determine if the net incremental increase in income is worth the effort and expense. 

Some of the saving on the 1's and 2's was done in small increments - for example, being more conscious at the grocery store to buy the store brand items when we could.

Buy at an extreme discount off the true dollar in a market proven to be able to rebound/appreciate rapidly.

Im guessing he is escalating in very small increments, like 1,000.

Do rehab on house and bring it up to level of rapidly rising neighborhood.

I also wouldn't do a lease longer than 1 year because your rental comps in the area might rapidly increase as the area develops. 

Your title calls yourself a "developer", so if you have activities you engage in that create earned income instead of just passive earnings, then that might qualify as self-employment.A Solo 401(k) can hold both tax-deferred and Roth funds, so you could do your ladder of incremental conversions over time in one plan.The Solo 401(k) would also have the benefit of higher contributions, potentially as high as $56,000 in your age bracket, depending on income. 

Of course, I’d be using the equity I’ve gained in the current house so I wouldn’t have that anymore, but do not see any issues with the new builds appreciating as this is a rapidly growing area.I’m looking to discuss any pros/cons, faults, suggestions to this plan.

I have no turnkey providers that I have used to accumulate these properties and have $160,000.00 cash flow and pushing rents and increasing NOI rapidly and Cash Flow too.