Probably, but most people aren't going to understand that LibreSignal is different from Signal. We could try to make things work differently for users calling LibreSignal, but that sets us on a path of having to constantly account for all the various 3rd party clients and their various stages of development or support, which as a team of two developers we unfortunately don't have the resources for.
Wouldn't it be possible to give better feedback to the caller in this case, such as the name of the client the callee uses?
I don't use Signal, so I may be missing something here.