I'm using Amethyst.

We're also talking about different types of notifications, too.

There are notifications that only show up in your notifications tab, such as when someone reacts to your note, and there are push notifications, such as for when someone zaps your note, which show up in your phone's notifications, even when the app isn't open.

Neither type of notification is available for say "subscribing" to a person's notes. You just have to hope you see the notes you really care about when scrolling through your feed.