Behringer X32 Core - Audio Routing with GP Instances

Hi all,
I started fiddling with instances, using the main instance for my keyboard rig and the second instance for a vocal fx chain. The audio interface I use in this case is the Behringer X32 Core (32in/32out). For now there is only one rackspace and I used the same two outputs (3/4 on the X32) in both instances.
I realized that I can route audio in both instances to the same outputs of the X32 and hear both WITHOUT connecting the two instances with the GP Relayer. Is this expected behaviour? Do I need the Relayer only to switch songs or rackspaces in all instances in sync? Btw I am on Win11.
Thanks!

Relayer is not needed to sync the instances.

Using OSC and setting the options and you are ready to go.

And with multi client ASIO you can route to the same output from different audio software.
Relayer is not needed.

Relayer is used when you want to send MIDI or Audio between Audio/MIDI Software running on the same machine.

Thank you, much appreciated!