I am searching how STUN/TURN servers entries defined webrtcendpoint.conf.ini file are used. I basically don't want to hard code the entries on JS side in constraints and want to define different STUN/TURN for different KMS instances.
So, my understanding is that if I don't define anything in JS, the entries defined in webrtcendpoint.conf.ini get used in ICE candidates eventually. Is that correct?
STUN/TURN configuration from browser and KMS are not related, unless you make the browser aware of the configuration from your KMS. The content of webrtcendpoint.conf.ini is only used for the media server to discover it's own ICE candidates. If you don't define STUN/TURN servers for your client, none will be used.
Kurento-utils-js library uses FreeICE if you don't define your own STUN/TURN configuration in your client.