I chose the Nano footprint because it’s the closest to a “standard” in the dev board world I could think of. You can get just about any microcontroller in that same footprint and the pins are usually in the same places.
The ESP32 nano will work fine, the only thing that won’t work with them is flashing code via the same USB cable because the ESP32 needs a sequence of reset pulses, but I’m working on support for that.
The Pro Micro will work as well, but you’ll need to cut the solder jumper RESET 1 because it’s tied to ground in the pro micro, and that’s connected to the other reset pin, RESET 0 so it will hold the board in reset and it won’t do anything.
Here’s where that trace is.
Then just put the board into the header all the way to the right.
There is some plans to make some expansion boards for the headers. If there’s a particular board you want an expansion for, put it in this sheet and I’ll make them when I get around to it pretty soon.