CBenson has pointed to the main issues of this discussion and the complicated details to having a standard assigned.
There is a need for guidelines with an understanding that those will not satisfy all of the issues in routing at this time with the current tools available.
I will give the example of my location between 3 unincorporated towns and a small city, I live in a section of strip annex of that small city, any address I search must be scrutinized to insure the route is not taking me to another location that is not even close or in the right direction.
I have been able to place pins and house numbers in waze and move Google pins as each comes needed in my travels, but that would be a huge undertaking to try and isolate each and every location.
However, it would be great to know if the city names are creating the issues on routing for the inner city boundaries, whether alt or otherwise.
Maybe a test area......we have one in Phoenix that would be a good candidate