For things like notifications, it's way too light, for the news feed, it might push CPU to 70% for 5 secs on each update.

I massively improved the next version, right now, I'm deleting all items in the view and recreating them, which takes CPU time, the next version will update the current items and create new ones at the top.

FYI, the news feed isn't refreshed unless the news feed window is opened once, to "delete" the window from memory and disable updates (till it's opened again), use CTRL+Q in the news feed window.