Like any neighbor issue, maybe the route with best chance of success is to try and talk to owners and establish a rapport and share concerns/ask if they would help you out.  

.- I'm happy to share my contractor, lender (conventional, construction, or hard money), property manager, etc. contacts if you do choose to continue investing in WA.

And hey, let's talk experience.

It continues to have a large housing shortage.  

There is no practical reason to talk to planning and zoning before reading and understanding this chapter in its entirety because you want to convey to the town official your plan and how it fits within the planning and zoning requirements. 

Also, when talking with different septic companies you can also bring this issue up as I find contractors to be very helpful when it comes to permits and the city or county.

As a house hacker myself, I am doing it at my wife and I's current duplex and will continue to do it for at least our first few properties. 

Were marketing people who talk on the phone and move paper. 

Let's talk about markets first:I grew up in upstate NY and my parents still live and there are a few things that are true of both this market and Detroit:No one wants to live there.

Your Attorney is providing you good advice, it is in their interest to continue the process and bill you.