Ports when natted and behind a proxy

So, I got the following setup:

Public Facing IP --> Apache2 as proxy for various sites --> Natted Network --> jitsi instance
I wonder whether I need to configure jitsi to use another TCP Harvester Port (like 4443) and forward this via iptables instead of using the default configuration (Port 443) so that it doesn’t also get proxied by Apache.

Any recommendations?