I have half a dozen Pi4s running in heat sink cases (various brands), as HTPCs streaming from a NAS, Octoprint server, Home Assistant server, and various heavie

I have half a dozen Pi4s running in heat sink cases (various brands), as HTPCs streaming from a NAS, Octoprint server, Home Assistant server, and various heavier load purposes. Since the earlier firmware updates I’ve never had any overheating issues at all, even after sustained heavy loads. Outside over-clocking or extreme edge-case stuff I think the “Pi’s NEED a fan” stuff is mostly leftover from the early days pre-update and just stuck around.