Smoothing: I was also able to remove remaining jitter by running the finished video through a stabilizer in AfterEffects.
Export: Perhaps the most needlessly difficult part of this process was creating the GIF from a high res MOV. I used photoshop this time around. However, I've recently started to quickly creating GIFs by uploading short clips to YouTube and then using Giphy's create feature: https://giphy.com/create/gifmaker
Test some other time-lapse approaches.
Investigate other uses for EOS Utility
Find the best method for creating small footprint GIFs
I've gotten pretty great reactions from the Gif. I think many people assume that I've faked it somehow. I think you can have good tech or bad tech, but in the end, the thing that matters the most is whether you've pointed your camera at something that is visually interesting.