For Raspberry Pi4 continuous selfhosted server operations: with and without case fan. This graph show a 20°C decrease, with a slow rpm fan.
The metal case has thermal stickers to reach for main components on both sides, and the fan is what I have in scrap parts, totally not for that case but pushes a lot of air with low noise compared to screaming mini cpu fans.
That’s what I said with “much hotter for longer”. If it’s constantly thermal throttling, that’s gonna be an issue. Of course OC’ing also will. 50°C just isn’t an issue. Also older models have CPUs that either don’t throttle at all, or do it less well/effectively.