To answer your main question: it's fine to minimize or totally turn off the permanotification. That won't affect the functionality of the app or the timeliness of reminders or anything at all.
Why have it all then?
The short answer is Google/Android made us. Starting with Android 8.0 "Oreo", Google forces apps that run in the background to have a persistent notification in the status bar. They want to make sure users are aware of apps running in the background. So you as the user can turn it off (again, to no ill effect at all) but we're not allowed to do that automatically.
Does Beeminder really have to run in the background?
This is kind of frustrating but it turns out that, yes, that's the only way to guarantee syncing and reminders happen on time, especially right before your Beeminder deadlines. If we could count on you always having data connectivity then we could solve that with push notifications, but we want to be robust to users being offline.
And the processing Beeminder does in the background is so lightweight that we're confident you won't notice any battery drain or anything. Definitely let us know if you see otherwise!
How do I actually turn the pesky thing off?
- Open Android Settings
- Choose Apps & notifications
- Choose Beeminder
- Choose Notifications
- Uncheck Permanotification
To just minimize so it at least doesn't show up in the status bar, you can just press and hold (aka long-press) the notification and then select "minimize" or "stop showing".
To emphasize one more time, the Permanotification is absolutely useless. You can and should minimize it or turn it off!
(Android may show a different notification if the notification is hidden, indicating that Beeminder is using battery in the background. Beeminder is using no more battery than before, but good news, you can hide this notification as well! Just long-press it and then select the option to turn it off.)