Ask your lender how they handle it.

Majority of DSCR Lenders do not allow Manufactured homes but do allow for Modular. 

Has anyone used them or any other lender for a 1st lien HELOC?

Also, if you buy using a hard money lender or cash, Zach Starnes can do re-fi's off the appraised value shorter than the typical 6mos and then you might not need any money down if you buy at the right price.

The lenders were very good and communicating at first, but as we got close to closing, we could not reach a single person in the company during business hours.

As a investment property lender we saw a lot of success with flips but an even bigger jump in BRRRR success with borrowers holding as long term and short term rentals. 

As for the "seasoning", some lenders will require the property to be "stabilized" (perhaps 80%-90%+ occupied, depending on the lender) for 3 months, 6 months, etc. before they'll do a cash out refi.

The current lender refuses to do a loan assumption. 

It depends on what the property appraises for in 24 months,  if you will be able to get home owner's insurance, if lenders are lending and so on.

As a commercial broker they are working with the seller the buyer, lawyers and the lender to name a few.