That's alright, I guess. I figured it out since then. Or so I had thought. I added a second keyframe to each channel in my animation that only had one, and that seemed to work, but the same solution didn't work for animation 3, which had the same problem.
I was on the verge of pounding my head through a concrete wall when I stumbled upon the solution by accident, probably the actual solution to all my problems all along - because I was using Shaper to import several animations without closing it once, I noticed every time I imported one, the number of keyframes it counted was going up, which was more odd because I had been deleting them out of Shaper whenever they turned out wrong. I was also led to suspect this was an issue when I noticed the file sizes for the exported animations seemed to be expanding regardless of what I was actually doing. I closed Shaper and restarted it, imported the animation to find it counted much fewer keyframes in the import window than before, and the animation exported at a much smaller filesize and ran perfectly.
So yeah, I don't understand if I was doing something wrong or if Shaper is just weird like that, but closing it between exports seemed to work.
While the fact that the lack of support for this animation process (I don't mean from you, just in general due to this being a relatively new thing) has left me completely confused for weeks as I left the animating on hold, I'm really looking forward to seeing how much this impacts the modding community. Perhaps one day we'll get some better official support for custom animations if this goes well.
Oh, there's your problem. Yes, Shaper stockpiles animations up... and even though you deleted them, remember that's just one of those issues with that problematic program. I'm sorry it caused you all those problems, and I really do hate having to use it, but as stated it's really the only way I've found to make this work.
Thank you, that's really encouraging to hear; I like how you say "impact." I too, am excited to see what will result from this project... I hope to see some add-ons using this resource within the next few months.