Which camera? Canon did it correctly. Heat pipe/passive cooling isn't good enough for advanced cinematography. Canon proved with the R5 that dedicated hybrid cameras have pretty much plateaud without active cooling. They shoved everything in there that's possible. Sony was forced to commit to active cooling in its new FX3. Nowhere else to go/improve in technology with a teeny weeny body. Sony has improved all it can do with the "Auto Pwr OFF Temp = High" setting. Even with advanced passive cooling they couldn't put advanced recording modes in their tiny cameras. Only limited ones. Leave the advanced recording to Cinema cameras. You want a smaller B camera, be content with it's limitations. There's no heat pipe that exist for unlimited recording of 8k 60p ALL I RAW internal video along with 4k 120 ALL I. You can have 8k 40 but not 60. Most all the variables were covered with the R5. Sony could only produce limited options. And certainly not the GH5 even with a smaller sensor. The most heat is produced to the rear of the camera (right center) in the vacinity of the processor. Reach down and disconnect your CPU fan in your PC and go with passive cooling and see what happens. Even the slimmest of laptops and Surface Pro computers have fans. Reason that tablets plateaud and only have limited applications. If one can't carry around a slim Surface Pro then they need some gym work.I like Sonys and Panasonics approach to optional ports very much. Including a top handle with a electronic connection to the camera. In the top handle you can include bigger and more ports if needed. Thats a great option to get a versatile, but still small camera.
Panasonic got the same idea for the GH5 - a digital audio interface that can be attached like a battery grip to the bottom of the camera. I think thats the best approach. Canon could put a heatpipe AND an audio interface in the grip, so we would have better heat management and fullsize xlr ports. It would be usefull for videographers, while purely optional, so photographers can enjoy that lightweight, smaller body.