So my real estate agent suggested looking into new modular home construction.

If it's working as an LTR and you are cash flowing, I'd be willing to bet that the juice won't be worth the squeeze in converting them to STRs. 

No pooling investors.. projects are varied from bare land to entitlement deals to new construction to BRRRR ( which is our bread and butter)..

It’s not necessarily commingling the entities to have them all as additional insureds on one insurance policy if there is a valid business purpose (think general contractor in large construction) but in this case it goes to an argument that they aren’t really separate entities.

You can use it as collateral if you want.There are also other loan options available for new construction.

Tear down current house and build single family with ADU and DADU and complete construction all at the same time. 

I found 2 banks that would back me in the project both offering a construction loan with no payments during the rehab.

I’ve got some multifam going on Long Island and I’m working on fix n flips in the Hudson valley, as well as new construction spec building. 

From what you laid out, a bank statement loan might be your best bet.

Lending: You bet.