I think I was able to have the data overlay and the sped-up video match up in one spot somewhere near the middle of the vid. I need to figre out a way to keep them sync'd up, it's pretty tough as-is. When Hyperlapse says "8x" it actually seems to be more like 10x, with a bit of variation as it goes along.
If anybody has successfully used hyperlapse with the garmin VIRB editor and gotten everything to match up nice, please let me know how!