I focus on content on our site so blocking part of internet with wordfence was brute but as life has only few thousands of weeks, it was the least I wanted to think about :).
Would you mind to share a source of good IP lists pls?
LLM's can help you implement iprange into IP list building scripts to keep the lists smaller and more efficient.
[1] - https://github.com/firehol/blocklist-ipsets/
Before pushing such things to production consider first testing in dev/qa then staging or some canary environment. I use those IP's to determine who gets into a moderator review queue so worst case it just makes more work for me. Consider using those in conjunction with whatever rate limiting capabilities your web server provides first so it is not a hard block in the unlikely event a real customer shows up on one of them.