@pkal @solene abridged version of my relayd, does this help? Can explain specifics if needed

log connection
log state changes
external_ipv4 = "45.63.99.239"
table <web> { 127.0.0.1 }
table <acme> { 127.0.0.1 }
table <avgen> { 127.0.0.1 }
table <orgy> { 127.0.0.1 }
http protocol "www" {
  match request header "Host" value "ols.wtf" forward to <web>
  match request path "/.well-known/acme*" forward to <acme>
  match request path "/avatar" path strip 1 forward to <avgen>
  match request path "/orgy-example" path strip 1 forward to <orgy>
}
relay "www4" {
  listen on $external_ipv4 port 80
  protocol www
  forward to <orgy> port 1337
  forward to <avgen> port 1338
  forward to <acme> port 8081
  forward to <web> port 8081
}