in Hyperion.ng the JSON Server port is always valid for all instances.
This means that the different instances cannot be addressed with the different ports.
But in Hyperion this is possible with the different configurations.
Example of use in my case:
First instance = Master (Port 19444 with forwarder on localhost 19446 and 19448)
Second instance = Slave (Port 19446)
Third instance = Slave (Port 19448)
So I always control only the first instance via app and the other two follow.
If necessary, however, I can still control the second and third instances separately in the app.
On the configuration page for the forwarder is also given as example = Example: 127.0.0.1:19446.
But it doesn't make sense to set a forwarder to localhost if the local instances can't have multiple ports.