So for those wondering on comparisons to other FOSS options:
Fittrackee (https://github.com/SamR1/FitTrackee): Very similar, but Endurain also seems to track weight vs just activity.
Wanderer (https://github.com/Flomp/wanderer): Also similar, but has social sharing and geared more towards trail recording like Alltrails. Also does not have weight tracking.
Note: Another big differentiator seems to be Garmin and Strava integrations.
Full rewrites do happen. The first commit of PiKVM is a copy of my repo: https://github.com/pikvm/pikvm/commit/70eebd5c59da26dc3f6ad56730adbb616055f4e5#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5R4. I was referenced there for a long time before eventually being removed, and I'm pretty sure by then my code had been fully rewritten.
Though I did find it funny when LTT covered them and said they complained about a copycat who wasn't giving them credit ๐