Wow. This is amazing. Able to boot into encrypted nvme without sd card 
Thank you @josch!
It was because I didn’t have the dip switch set to ON when I was setting the boot config. After doing that, as well as using the ROOTPART env var as suggested in the docs it worked.
Once I get my reform fully setup and have some time I’ll attempt to make a PR for the FIXME you have in the docs.
I’m thinking it makes sense to add another step to the reform-setup-encrypted-nvme script that asks if you want to boot from SD or EMMC and then warns to say ensure the DIP switch is set to ON.
Any thoughts about that? Don’t want to attempt something that doesn’t make sense for the way this is designed.