Great that it doesn't run.
Does the material resume it's original appearance and properties when it cools down to room temperature?
What we would need is that it will still remain a barrier to water for the metal on which it is applied, before after the heat excursions. With the Dow Corning stuff, you couldn't tell afterward that it had ever been heated. I notice your sample doesn't glisten the same before and after the test. But, you may be going beyond the temp that it is expected to survive without a property change.
Still looking like a good substitution, though. It would be very interesting to see how the Dow corning stuff would fare in your test oven. But, I'm guessing it would fare about the same. I only went to 500F in my tests. The display numbers on your oven are in degrees C, right?
If you have an old caliper seal, it might be interesting to see at what temp that seal gets destroyed. To my reasoning, the grease only has to withstand the temp range that the seal can, (and not run and survive). That, and maybe the glue used to bond the brake pad to the steel backing.
Nice work!
Cheers,