My additional ESP32 bits arrived today as well! I had to solder the headers onto the ESP32-S2 myself, and while it's not an amazingly neat job, I think it should get the job done.
There we go, my ESP32/e-ink setup is done! This one is living in the office so we can see the current outdoor and indoor temperatures at a glance.
I chucked the code up on GitHub because there was a bit of trial and error involved: https://github.com/VirtualWolf/featherwing-temperature-displayer. This is using CircuitPython not MicroPython, and there's fewer resources available and fewer people using it, it seems.