IMHO you're being unrealistic with your expectations and it's pretty clear that Orcon is not targeting the type of customer you are.
The NF18ACV is a great device deployed by a number of different RSP's but it's clear it doesn't suit your requirements. The great news is there are 80+ providers of UFB service providers out there with plenty of smaller and specialist providers who will meet your requirements and allow you to deploy your own WiFi solution that meets your requirements. My suggestion is to look at one of them.
There is not a one size fits all solution for covering a large property with WiFi, and Google WiFi is NOT the answer to many problems either.