I can’t tell if you are trolling me, but obviously “we made this single-threaded thing multithreaded” implies new algorithms that need new test runs

I am just evaluating your logic in the form of a reply, so you can see it at work. The same issue you describe happens often across multiple versions of a system.

The part of Redis that were Jepsen stressed, Redis-raft more recently, and Redis sentinel, for which the numerous flaws were pretty much summed at "as designed". No part of KeyDB has gone through a Jepsen style audit, all of which are untested bespoke algos.

Chrome is based on a fork of Webkit. Are you going to trust it because Safari passed a review before the fork?

Ask one level higher in the thread.