Honestly, I don't know.
If algos are not standardized then relay operators that want algos will pool all messages from all relays to provide the algo with a full result set (they already do this). They do this because as a user I don't want to see the best stuff from just 1/10th of my followings, just like I don't want to use a search engine that searches 1/10th of the internet in its own way, and then I use another search engine for each other 1/10th.
You can get "consistent" algo results one of two ways on nostr afaict:
1. pool notes on mega relay, run your special algo
2. on that notes that each relay has, run a standardized algo, combine them on the client
According to The Man I'm wrong about something. I can't tell what though.