If you recall when the rates jump super quick a few years ago many of these same hedgefunds/insurance companies just one day decided to stop lending all together until rates stabilized..

My goal is to understand the current demand and rental potential for ADUs in this part of the city, as well as the costs involved in building.

There is work involved as you have well found out. 

.- Stabilize the foundation with helical piers on the exterior. 

If you have significant resources you can start on your own, if not partnering with someone who brings some local knowledge can accelerate and stabilize your journey. 

It took about a year and a half to stabilize the property but the property is stabilized and cash flowing.

This usually involves putting down 20% down payment on 150K-170K houses.

Might be a little bit confused here, but from what it sounds like you were involved in purchasing the property, renovating it and then selling it?

If there are any anomalies that occur which require more expensive repairs then that ratio can and will be higher, especially in your first year or 2 of owning a property as you work to get things stabilized. 

Alternatives to ConsiderIf you want to involve an entity for liability protection or other reasons, here are some potential approaches:Assume in Personal Name and Transfer to Entity:Assume the loan in your personal name and later transfer the property title to an entity.Important: Transferring title may violate the loan’s due-on-sale clause unless explicitly allowed by the lender.