If you don't have a need to be notified instantly, you can set your notifications to "start periodically". Doesn't use much battery and better privacy.

They're working on it. It's not actually one single problem, but the cumulative effects of several different things. We've been trying to convince them to integrate UnifiedPush via custom ntfy.sh services, and they're starting to take the idea seriously, which is promising. If they do that, 90% of the battery drain issues will be resolved.

Yes that's where my setting is currently but I miss voice calls like this...

Yeah. I think they're worried about metadata using ntfy I think ,right? Let's hope they get the ball rolling quick.