Hi Jason -
It is a bummer that the Bluetooth icon was demoted from the status bar in iOS 12.
In general, Go Button does not directly communicate with Bluetooth devices. When iOS receives a message from Bluetooth hardware, it just gets forwarded to Go Button when it is the front-most app. Once received, it is translated into an app action according to the mappings in the current remote control profile.
To display a Bluetooth status icon somewhere inside Go Button, we would first need to see whether a third-party app can request that information from the device or not. We appreciate the suggestion, and I'll make a note for us to do some research into what tools we have available!