The Dispatcher has been Adobe's/CQs standard Load Balancer. Not sure why you say you've never seen it as an LB @Jörg_Hoh It's like in the front of the documentation and what Adobe has recommended from the start beginning with CQ5 https://experienceleague.adobe.com/en/docs/experience-manager-dispatch...

AEM does not allow us to use the JSON extension.We always have to use it on jcr:content.custom.jsonwhen the extension is .html we can hit the page directly but if its anything other than that we have to hit jcr:content Any clues as to why it behaves this way ?

Did you get a solution to this? I am currently facing the same issue right now