Just to clarify, the integration I would like to have is:
Yes, that wouldn’t be possible right now since the Dashboard API works in the context of an organisation, so the keys format is constrained by this, hence why the Gateway API is needed. It may be feasible for the Dashboard Admin API to be extended to support this.
What you are proposing looks like this.
Yes, that would work. A slight variant would be for the legacy key management to target a single Gateway, if that is easier for you. Since the Gateway writes the key into Redis, any Gateway connected to the Redis will be able to read it, so you don’t need to push the key into each Gateway separately.