I just wanted to add my experience for the record and for whomever it may help ease their minds.
I have an EVGA GTX 1070 SC which I've used since 9/27. According to the serial number the card was shipped 6/21. I've ran this card with +100 on the core, +500 on the memory, and 112% on the power limit at a constant 80-85°C (when gaming) for the past month or so. I live in a hot humid place and I have a small cramped case which explains my horrid temps. Also I'm the second owner of the card, as I bought it off of someone else who probably used it as much as myself. ALSO, I ran my CPU stupidly hot for some time as I let the voltage on Auto when I OCed and temps were craaaazy inside my case for like 2 weeks until I finally undervolted the CPU. As of today (knocks on wood) I have had zero black screens, zero graphics driver crashes, zero throttling, and of course no catastrophic failures. And as I observe the gpu from the front (where the evga light up logo is) I can see that the pcb components are in contact with what I think are thermal pads which in turn seem to be in contact with the mid plate.
Nevertheless, as of today, I have returned my GPU OC settings to default and I've ordered the thermal pad kit just to be safe.