I used lsblk (also confirmed using disks) that my EFI partition is /dev/sda1. Oddly a df -h doesn't show sda1, it only shows sda3 (with sda2 being swap). I also trieddf -h /dev/sda1 but that shows the size for devtmpfs (4mb, and I know my EFI is 512mb) How do I know full the EFI partition is?

      The boot partition is only mounted during updates and unmounted immediately afterwards. You can mount it manually by running sudo clr-boot-manager mount-boot which will then allow you to see the free space.

      Axios Perfect. I didn't even think to try and mount it there.