Hi, Logan--
Thanks for testing it out; I have squashed that bug now, and pushed the new version to the git repo. It will be in the next build (which will probably be soon/this weekend); if you want to pre-empt that, you can grab "lib_b0_corr.py" from the repo, and you should be aaaalll set. As a bonus, the blur sigma is now also output in the *pars.txt file.
Also, all credit for this B0 correction work goes to Vinai "The Corrector" Roopchansingh; merely translating his work on this.
thanks,
pt