So if the owner wants everything to be ok, he should open the card and change the paste/pads and yes, the warranty will be void.
And only a small % of users will do that and prefer to live in denial. Some of them not observing the degradation and will just upgrade faster their GPU blaming something else rather the high temps which was "officially supported"
Till you remove at least back plate and change pads with thermal putty and add more, covering wider areas just stick a 92 mm fan or 120(only if your card is 14 cm wide) in pull on the back plate aprox @ 1000 rpm, also increase rear case fan RPM.
I also cut the grill, way too obstructing in my case.
Edit: use the rubber mounting pins to set the fan height on the card more than it shows in the video, at least 10mm height. Is more efficient.
If you have issues like me with trapped hot air coming form GPU heatsink exhaust, trapped in between the card and side panel, angle the fan or use 120 fan and move slightly over the edge of the card.
Targeted airflow always worked in my experience.
Just in very few instances airflow pressure inside a case is so powerful to efficiently cool a hot backplate.
If a setup as above doesn't work or is just lowering 1 C, than we have:
1.Poor quality pads
2.Pads are covering very small area, not enough for back plate to really take all the heat traversing PCB(fast enough) and is acting more as a heat trap.
3. Plastic film
inside the backplate, not the one you have to peel, please, the other one.
4.Lack of pads
5. Secondary plate without thermal links in between > Sapphire