endwall_raspi.sh
I set up a rapberry pi 4 model B on Raspbian 11. I modified endwall_wifi.sh, and got it working. I have uploaded the iptables configuration that works for the raspberry pi on Raspbian 11 Bullseye and called it endwall_raspi.sh.

http://nguipxnkrp3qrzrlduhsatpcpwehnblzmlkc5ifiumxq4z5jlh4lwvid.onion/endware/endwall_raspi.sh

I tested endstream.sh from wifi and it works well. The audio works as well through HDMI. This will make a good multimedia streaming device.

Also Debian 11 bullseye switched their firewall system from iptables to nftables, so I'll be looking into translating endwall_wifi.sh into nft,sometime in the future, probably over the summer if I have time.