"-is" is typical 3rd declension. If it's not neuter (how do you pick a gender for loanwords in Romance languages?), it'd be Redes. If it's neuter it'd be Reda as you said.
Or maybe it'd follow the -eris pattern and be Rederes or Redera.
Sorry I was just being pedantic on a Friday afternoon. The rest of the blog post was great and I agree with all your points. I've been advocating for immutable cache keys for years, for the exact reason you mention.
If we're playing Warhammer 40K, the chapter keeping all these Redises around the galaxy alive might be called the Cachess Redisari. Now I wanna see what happens when get a little too twisted by the chaos.
Or maybe it'd follow the -eris pattern and be Rederes or Redera.