The problem temperature is 260°C which can easily be avoided by not heating an empty pan (oil/liquids will distribute the heat more evenly) and you'd be unlikely to want to cook at that kind of temperature.
Teflon is not very thermally conductive, so the bottom contacting the metal substrate may be at a significantly higher temperature than the top. Chemistry reactions have activation energies, and you can generally always trade temperature for time. If it happens in a minute at 260 C, it will still happen at 200 C, just slower.
> If it happens in a minute at 260 C, it will still happen at 200 C, just slower.
I don't think that's particularly accurate unless you're considering the action of individual atoms. e.g. Water is considered to boil at 100°C but there will be some water evaporating at lower temperatures but this is a different process that only occurs at the surface. I don't think it's accurate to say that water is "slowly boiling" at low temperatures unless you're reducing atmospheric pressure.
The result is the same though. The water leaves the container and enters the atmosphere as vapor. You can call the former "decomposition", and the latter "leaching", but you are eating the degradation products either way.
Because of the way toxicity works happening slower is quite relevant. Similarly if you drink a bottle of vodka slowly enough you will have no significant health effects but if you drink it in 2 minutes then it’s not going to be great.
Different poisons have different accumulation characteristics. The relevant part here is that perfluorocarbons are fairly persistent in your body. Your body needs a few hours or a day to process the vodka, but the PFAS in your blood takes months/years to leave your body.
Good luck with that. Temperature isn't perfect and hot pockets of higher temperatures form.