Create BindableService or ServerServiceDefinition from within Kotlin source

For implementing a gRPC-service into the framework, I need to pass an io.grpc.BindableService to the addService method on the ServerBuilder which basically provides io.grpc.ServerServiceDefinition.

To get this info, usually you extend some kind of ImplBase that has all the methods to gather this. You can achieve this by enabling this option: grpcServerCompatible = true
I have been trying this in this issue: https://github.com/square/wire/issues/1903

But honestly I prefer not to generate all this "legacy" code, but just stick to the Kotlin generated files and provide the BindableService from there. Is this possible - and if it is - how?

I tried to create something myself, but it's hard.

    class Greeter : GreeterServer {
        override fun sayHello(request: HelloRequest): HelloReply = HelloReply(
            message = "Hello"
        )
    }

Start by reviewing ServerBuilder.addService, BindableService, ServerServiceDefinition, and the Kotlin-generated GreeterServer example described in the issue, then compare the grpcServerCompatible approach referenced in issue 1903. Done would mean a documented or implemented way to obtain a BindableService or ServerServiceDefinition directly from Kotlin-generated sources without generating legacy code.