Hi @Hunaluto, this is up now (the 4.17-Purism-1 branch was there but it is now merged to master): https://source.puri.sm/firmware/utility/-/raw/master/coreboot_util.sh. Thanks for your patience while I took the time to ensure everything was properly tested!
I am indeed taking over for Matt, so feel free to ping me here or at jonathon.hall@puri.sm for any firmware questions 