The ADU now covers over half the mortgage + additional monthly income per horse the tenant desires to keep on site.

Depends on the bank, some due a lower LTV and get you a HELOC with no site visit and others do a site visit with higher LTV.

It's in a popular year-round tourist destination with a shortage of hotels and heavy restrictions on STRs. 

https://www.biggerpockets.com/blog/short-term-rental-loans-a...DSCR Loans: Terms to Know When Working With These Popular Rental Loanhttps://www.biggerpockets.com/blog/dscr-loans-terms-to-knowWhat’s Next For DSCR Loans?

So newbie question - you basically have to get your GC (if you use one) to come to every potential site and ask for an estimate?

I have seen sites like CreditKarma or Credit Cards under-report and over-report consumers scores, so they are not the most accurate.

I watched a video/podcast once that showed a tool/site which allowed you to see what amenities the most offered amenities were in any given market/area ranked from highest to least (like A/C, pool, grill, etc).

All other sites it's 100% to save us time and hassle. 

Account Closed, our new Chief Product Officer, has already started to go to town bringing this site into the 21st century.

Even Zillow acknowledges their Zestimates can be off by as much as 10% (you can read more about this on their site).