Performance and energy impact of background tasks

I'm curious as to what the performance and energy impact of SB is, particularly in offline mode. I see these on the console every few seconds:

[Service Worker] Got error fetching, throwing offline /.ping Failed to fetch
[Service Worker] Got error fetching, throwing offline /.fs/Journal/2026-02-09.md Failed to fetch
Uncaught (in promise) Error: Offline

Should I be concerned of the energy impact on this on battery based devices? Does it continue to happen even when focus is shifted to another application? Is there a way to disable this?