My view is you have incorrect risk assessment especially if this is in a single family zoned area.Here are some of my thoughts- 2 ADUs disqualifies from Fannie/freddie conventional residential financing even if both are legal. - appraisal could come back subject to corrections. - unless you get some whacko judge, there should not be any issue collecting rent on unpermittted unit, having a move-out cost (no fault eviction) in excess of the standard rent control or eviction process in excess of standard rent control hurdles.    

I owned multis in residential zones where people have home based businesses, successful, then hired employees.

I am originally from UK and after 6 years I now qualify for funding and I am wanting to house hack a multi family (seems like a cheat code as it isn't an option on a residential mortgage in the UK) but the issue i am finding is the low inventory in my area (6 listings within 20 mile radius of Danville VA) and nothing that i think i can make cashflow well / or seems like it would rent to a decent caliber of tenant. 

(i.e. if the tenant moves out, the property could be converted to a long term residential rental or STR with enough margin for you to hang on to the property until selling makes sense)Keep us updated on what you decide!

By no means should this be interpreted as an anti-BRRRR post.  

It’s off of a very traveled road with frontage, so it could be used for commercial or residential according to the zoning. 

For anyone else there are 3 rules for investing in residential property in NY.1.

I've witnessed several "historic" buildings try the residential above and office/retail below and have major tenancy issues.

Is an estoppel certificate something you want to do only for commercial properties or should you also do it for residential ( duplex, Triplex, quadplex)

A quad plex is still a residential property so easy to qualify for if your living in one unit for a couple of years.