Yeah, he has some pretty interesting stuff.

But AVX512 transition latency is pretty different from clocking up from idle. The CPU is already running at full tilt, and is making a relatively small frequency/voltage change. You can see from his writeup that it's well under a millisecond. I believe newer Intel CPUs have done away with AVX-512 downclocking completely.

I probably won't be able to look into that specific issue since I don't have any AVX-512 capable CPUs.