Just a couple notes, based on my own build and what I've read here:
1. No need for the capacitors with the OKR chips (the TI chips do, though)
2. You should use a MOSFET with a low amp button, or a normally closed button (plus a pull down resistor) if using pin 1. It looks like you have used both. I used a 3amp button between battery and pin 2.
3. I'm pretty sure the zener is not needed, but I didn't use pin 1.
Anyone else, please feel free to correct me, it's been a while since I used an OKR.