I've got few of the model 4, though most of my Pis are earlier models. Earlier models I rarely had a fan involved, but the first two model 4s I used, I put on

I've got few of the model 4, though most of my Pis are earlier models. Earlier models I rarely had a fan involved, but the first two model 4s I used, I put on a big metal heatsink that included two fans. For my purposes the fans seem to be fine to be disabled, and the device doesn't throttle back due to thermal overload. However - the heatsink takes up a lot of space, and probably can not be used with this kind of hat, so I'd have to look at a less passive cooling option I think. Also, where I'd be deploying something like this would be in a part of Australia where through summer ambient air temperature can get around 50C, and if it's in a shed or covered area, perhaps higher. I haven't had a Pi4 running here through a summer yet, so have no idea how that's going to play out. In about two months from now I'll have a better idea.