I see the ESP32-S2 has a 'Time-of-Flight' mode - I understand the software for this is not ready yet but can anyone official comment on how this works? Is there some kind of hardware timestamping support on the wifi PHY?

Thanks for the reasonable response! It's difficult for me to know as an outsider just how long the development process takes, I'll sit back and relax for a few months.

What's the latest news on this?

I don't have an exact solution for you, but I though I'd post just in case it gives you an idea for a solution. I've just brought up a custom PCB with exactly the same SD card IO that you're using. My trace length differences are up to 300 mil. I have a 22uF decoupling capacitor on the SD card 3.3V,...

It sounds like all the important points have been covered, so this is merely another vote for the following: The minimum: - More pins (no need to go crazy, 6-10 or so is fine). - No overlap of bootstrap pins with normal IO. Or the requirement for bootstrap pins eliminated (somehow). - All the hardwa...