Same here. Worst thing that's happened is when it refuses to load a site until I restart it after a background update, which kinda kills my flow for a second, but at least it restores the session immediately. I have noticed something on some of the more sketchy sites in which resource usage spikes, which I am guessing is some new abuse of workers or something. The uneducated conspiracy theorist in me assumes some magic crypto mining background thing that uBlock hasn't identified yet, but I haven't been bothered to investigate since it's rare and brief.