48-52C is GPU core temp. You did not see GDDR6X temperature because nvidia has not released the sensor API for linux-based OS. Which is why you will only see one temperature on NVIDIA, while you will see two on AMD cards.
GDDR6X can hit 100C easy. What’s more on the EVGA card, there are GDDR6X memories on the bottom layer that only has the metal backplane to sink all the heat. As to why this can pass any form of safety and fire hazard regulation beats me.
I have a EVGA RTX 3090 FTW3 mining with a custom made copper blocked that was CNC’d to the dimension of the backplane…mining ETH at 115MH @310W, 1400 mem, -300 core. This is with a 240Vac fan blowing air laterally along the copper block… i have not dared to push the power beyond 330W or 2000 mem