I am only bringing up the risks because I want to make sure others fully understand the situation.
Deco: how warm does your amp case get? Mine certainly gets warm but nothing I would remotely consider hot. I am considering the thermal paste as well since the case is so small (a quality which I like). I also got one of those iec inlet covers for the inside. One of these
https://www.digikey.com/product-detail/en/schurter-inc/0859.0075/486-2029-ND/1730687
I wonder what other small tweaks one can make.
The thermal paste really helps to transfer the heat from the amp module to the case - under sustained load it will get fairly warm, very quickly - which is good, since that means the heatpaste is effective in transferring the heat to the case.
Between the circuit board and the amp metal backplate of the module there are thermalpads pre-applied by Hypex in several places. For those who want to really make 100% sure to ensure the best-possible heat transfer, it might be worthwhile to temporarily remove the backplate, and replace the applied thermalpads with higher quality thermalpads such as the ones from Arctic.
On this amp I've used Arctic MX-4 thermal paste, which I usually use on 'Monster' Noctua Ryzen Threadripper coolers, but any non-conductive thermal paste should do just fine.