From there, I would like to consider a 1031 exchange in the future to acquire more units.My current property management company suggested that they could handle a mid sized apartment building but I would absolutely not consider them for it as I believe they have overextended themselves and communication is lacking.

I am a Jacksonville broker with experience with 1031 exchanges, but these properties are in 3 separate markets.

If not, I'll have a property I could 1031 exchange or just sell. 

Be mindful of short-term capital gains tax, as profits from flips held for less than a year are taxed as ordinary income, and frequent flipping may result in self-employment taxes.While profits from flips do not qualify for 1031 exchanges (since flips are considered inventory, not investment properties), you can minimize your tax burden by deducting allowable expenses like renovation costs, loan interest, and holding expenses.If you're considering diversifying into rentals, explore opportunities to benefit from long-term tax advantages such as depreciation and lower long-term capital gains rates.

Cash purchase, 1031 Exchange How did you add value to the deal?

You’re paying $70k in “non-deductible” interest in exchange for less deductible interest. 

The ultimate tax hit is at most $5k (20k * max 25% tax rate) and it's probably not worth it to 1031 exchange for that little of tax deferrals.

But to answer your question, yes you can use a DSCR loan on a 1031 exchange transaction.

@Blake Kirby I just finished the first half of a successful 1031 exchange for BP clients from California...the second fourplex closes early next week.

A foreign national loan should work.