I found out about Lynis(https://cisofy.com/lynis/) through a Mastodon post. Using this system analysis tool alerted me to all sorts of hardening techniques I hadn't used before. Some I was able to implement. Others were a bit beyond my skill. Some checks I deemed a bit much and was able to set the config to skip those tests. On one of my machines, I just wasn't going to reformat the whole drive to separate out the likes of /var and /home and others into their own partitions. I'll keep that in mind when I rebuild.