In the realm of firewall applications, i use the following: ° Ipfire is easy to use, but lacks ipv6 support and it doesn’t have otp. It has lots of packages though.

° Alpine is good, if you don’t want a GUI or want to spend time figuring out how to build a web ui (really good for beginners as its mostly xml)

° openwrt is good fit for low end hardware (SPARC or arm processors mostly) but also works on x86.

° opnsense - like pfsense, but more up to date. Has some quirks in it (like if you block both incoming and outgoing, but just want to allow 80/443, the rules look weird…like the direction you have to allow is in, but destination is 80/443. Very strange bug that isn’t in pfsense).

° hardenedbsd firewall - literally just opnsense but with hbsd’s fully patched kernel. No repo though.

That being said, you can make any distro a firewall, just use iptables/pf/ipfw/ipfilter rules through command line, and you can add anything in that distros repo you can think of.