I followed the same procedure successfully, and had a couple of things to add:
1. The F800 Pro has an optional hardwiring harness that works without a powermagic. The hardwiring instructions for it can be found here:
https://www.thinkware.com/Support/Faq?cat=MOUNTING
2. The heater-S fuse does not work for me --the owners manual says that it powers the air conditioning system-- but the seat heaters worked for continuous power.
3. The Toyota service manual at
https://demos.starbase7.net/t3Portal..._rm_index.html tells you exactly how to remove the A-pillar. I looked under Vehicle Interior > Interior Panels > Roof Headlining > Removal > Remove Front Pillar Garnish.
4. When putting the A-pillar back together pay special attention to the middle clip; otherwise the top clip doesn't go in properly.