This 4-bedroom, 1.5-bath brick bungalow is currently tenanted with a long-term tenant of 5+ years, generating $900 per month on a month-to-month lease.

I wouldn't call that a true "DSCR Loan" - especially considering that a ground-up construction property won't have any cash flow so DSCR would be negative or 0 numerator if you'd try to calculate it ground up multifamily is not 0 cashflow there are hundreds of thousands of apartments built every year, leased up, and sold for a profit as well. we build not only at a discount for investors but 1% on infill lots I'd be really careful with all your absolutes. you can get land for 10k in columbus on lots you can build 2-4 units on in one of the cheapest construction markets in the country.

Oh and Lane is on Biggerpockets and frequently posts so try tagging him as well. 

I've been using various lease option strategies for 30 years. 

Question: what is the $2k for re-leasing costs?

Are the leases even valid, if they are not signed by you or your property manager? 

This 4-bedroom, 1.5-bath brick bungalow is currently tenanted with a long-term tenant of 5+ years, generating $900 per month on a month-to-month lease.

I also have a few leasing agents and buyers agents that have my information and get a lot of mid term rentals that way.

What is the best way of smoothing the transition and aigning a new lease with increased deposits and rents?

Sometimes condos have stipulations in their deed restrictions that go against doing short term leasing, so I would definitely get your agent or do the research yourself to ensure this isn’t the case at the building you’re looking at.