Use swag with non-standard ports (to coexist with caddy)?

I have got swag working perfectly with all my subdomains using the standard ports 443 and 80. However, I am also trying to run a new (still in alpha stage) app for which the developers have supplied a docker-compose file and an environments file. This app uses caddy, which uses port 443. So somehow I need to get swag to coexist with caddy. If I change the ports for the swag service in my docker compose file:

  - 4443:443
  - 8085:80 #optional

for example, what do I need to change in the proxy-confs files? Do I need to replace at least some of the ports 443 with 4443? And if so, which ones? (I’m sorry if these are idiot questions…) Many thanks.

Running SWAG on non-443 will give you various issues

Why not switch the other app to a different port? Or proxy that through SWAG?