oh i'm sure the cooling effect is >0, just saying the normal use case for this kind of cpu cooler is directly onto the package, not usually through several additional layers. If the case is used as a heatspreader you might even be better off sticking a ton of these all over it.
Also, I would add a few of those (https://www.amazon.ca/a14111400ux0242-Aluminium-Radiator-Heatsink-100x25x10mm/dp/B00UJ95TOE/) heat sinks with thermal tape or paste. With the big size fan on top or a clip-on fan, this will help dissipate the heat very fast.
If people want to test the performance and temperature change, I would really appreciate that. I'm pretty sure I will end up using a cooling like that.