Now that I actually have my Framework and those heatspreaders, I couldn’t dare to use them. There is just no room, not even for 1mm of copper.
I broke out the micrometers and measured 4.17mm from the mainboard base to the top of the cooler, which seems to be the component that stands tallest. I then measured 3.39mm from the top of the M.2 to the mainboard base. That’s a difference of only 0.78mm. No way was I going to put a 0.5mm thermal pad plus a 1mm copper plate here. I thought it would cause the copper to push against the underside of the lid.