Great to hear you got it working.
As for the reasoning behind this, I think it has to do with legacy. Axon Framework has been around longer than Axon Server, and multi-context is something that came into being much later. It’s actually implementation-specific for the DistributedCommandBus, so that might also be the reason it’s not part of the generic CommandBus or CommandGateway interfaces.
Having said that, we are always looking for improvements and we will start working on Axon 5 in the near future. It would be great if you could suggest this here: Axon Framework 5 suggestions - #11 by Gerard