Thanks for mentioning Fort. I've never heard of it but I'm an avid user of Simplewall. Looks like I will need to take a close look now. Thank God it's not another crapp written in Electron.

Used https://tinywall.pados.hu/ when I was on Windows (at least a decade ago).

I would recommend Fort, back when i ran windows i tried all the available firewall and simplewall ended up being buggy after some times.

Fort worked perfectly, it had more settings and once you took the time to set it up you could just save the rules, the configuration and export it to another computer.