Do you think it is safe and secure to disable Mitigation in Fedora for the sake of performance?
I've seen a video from CTT demonstrating the <10 performance boosts by simply off the mitigation. The system will be secure for personal use as before.
The short answer, as a ton of people already said in the comments of the video, is "hell no" it is not and it is most likely also not worth it. Back when the video came out I tested it (with unplugged network) on my system and the performance gain was ~1% which I'd consider well within the margin of error