Should I be using FIREWALL_OUTBOUND_SUBNETS?

[PrivatePasta]

I'm trying to run a service called Acestream-Engine which is a BitTorrent application used to broadcast and view live streams. I use a lightweight Docker container that runs Acestream-Engine with network_mode set to Gluetun. Without any changes, Acestream reports got socket error and send_multicast_pex_announce error messages. After some Googling I came across this comment on an issue blaise-io/acelink#85 (comment) which mentions that if I use FIREWALL_OUTBOUND_SUBNETS=224.0.0.0/4 in my Gluetun config, it fixes the issue, which it does. But the commenter also mentions that it will leak traffic

To be clear, I am not asking for support on the Acestream service or its issues. I'd just like to know if I am leaking traffic or indirectly causing a security issue by using this setting, What does it actually change?

My current Gluetun config for reference:

image: qmcgaw/gluetun
container_name: gluetun
cap_add:
  - NET_ADMIN
devices:
  - /dev/net/tun:/dev/net/tun
ports:
  - 6878:6878 # AceLink
#   - 8080:8080 # qBitTorrent
#   - 8388:8388/tcp # Shadowsocks
#   - 8388:8388/udp # Shadowsocks
volumes:
  - ${DOCKER_VOLUME_CONFIG}/gluetun:/gluetun
environment:
  # See https://github.com/qdm12/gluetun-wiki/tree/main/setup#setup
  - VPN_SERVICE_PROVIDER=private internet access
  - VPN_TYPE=openvpn
  - VPN_PORT_FORWARDING=on
  # OpenVPN:
  - OPENVPN_USER=xxxxxx
  - OPENVPN_PASSWORD=xxxxxx
  - TZ=${TZ}
  # Server list updater
  # See https://github.com/qdm12/gluetun-wiki/blob/main/setup/servers.md#update-the-vpn-servers-list
  - UPDATER_PERIOD=24h
  # Control Server
  - HTTP_CONTROL_SERVER_AUTH_CONFIG_FILEPATH=/gluetun/config.toml
  # Firewall for AceLink
  - FIREWALL_OUTBOUND_SUBNETS=224.0.0.0/4
  # HTTP Proxy
  - HTTPPROXY=on
  - HTTPPROXY_USER=xxxxxx
  - HTTPPROXY_PASSWORD=xxxxxx
  - HTTPPROXY_STEALTH=on
  # Blocks:
  - BLOCK_MALICIOUS=off
  - BLOCK_SURVEILLANCE=off
  - BLOCK_ADS=off
    restart: unless-stopped