I recently upgraded from AC18 to 22. When I did, the custom mouse configurations which I set up in System Preferences also migrated. So far, so good.
When I went back to work on a project in AC 18, the custom mouse configurations were gone. I tried to add a new set of configurations for 18, but it defaults to 22 only. In previous upgrades, the configurations stayed with the multiple versions of AC, so that I was equally productive in multiple versions. After more than 15 years, i don't want to retrain my hand.