I got it working late last night!
The main workaround that it required on windows was adding Spork to the gemfile. I tried a lot of fixes (for gems not loading, rake related errors, etc.), and I'm not 100% sure which ones ended up contributing to it actually working. Hopefully, I'll install it on our windows PDM server in the next few weeks, as well as better document the process for beginners.
Thanks again to Pat Fairbank! His support and help was extremely valuable to me.