If not, pay off the mortgage all at once.This will help keep you from rationalizing a bad rental purchase just because you earmarked the funds for it. 

It seems I am a going to be a middle man between a wholesaler and another licensed realtor.

Its a tough subject because logically, they are joint and several guarantys so rationally a 100% guaranty from each of two people (one 740 one 680 for example) is ALWAYS going to be better than just one 100% guaranty from someone at 740 (so it wouldn't make sense to have a better rate for the latter)The problem is that there is fraud and "straw borrowers" out there where someone who is not involved in the property signs on to boost score and terms - so many DSCR Lenders in response either do the "non-rational" thing and price to the lower to avoid the fraud or use the higher of the two (and either be a little loose with things or just stay vigilant on any funny business)

Wholesale deals where you are the middle man might be the way to go.

Many borrowers think they can “cut out” the middleman (mortgage or loan broker), save some upfront “points” and fees, and go direct to a lender.  

I've had HUD forms filled out billing me for pro-rations that were the seller's responsibility, agents who have lost track of contingency removal dates, ... the list goes on and on.

There is no rational debate I could ever have with you, because you ignore everything negative relative to crypto. 

I'm assuming it's because the wholesaler is basically the middleman?

If so, the income on your tax returns will be positive so the whole rational of trying to avoid the income is moot. 

I have dozens of clients doing this in New Jersey most of which come from no construction background, they simply use preferred vendors we have in place (not GC's) which lowers renovations cost because there is no middle man.