Can anyone explain the differences between the Blackbox x4 and x32? Why would one need/want the x32 over the x4?
If you have a 4X there's less of a need to upgrade. Its a gentle evolution of the line. Same thing. Just newer. If the 4X works, keep going with it. If you wanted to add a 4th axis rotary, the X32 would be a "need" Wifi is nice, but USB is great too. Not really a need that one grblHAL is more powerful than grbl but if you are just running a plain kit machine, you won't use the advanced features. Think of it how car manufacturers brings out new models of the same car. Just a gentle modernised update
And I assume by adding the OpenBuilds Interface I can eliminate the communication points; WiFi and USB?
Yes, Interface makes the machine standalone; see https://docs.openbuilds.com/interface to learn more about it
