Okay, I've figured out a sort-of solution: I created SVG's using the tutorials I described above, and it works! Kinda!

When I open it in a browser, everything works great, except that the image doesn't scale:

https://gfycat.com/entirevainindianpangolin

When I try to insert it into various software, like TiddlyWiki, it scales and is actually useable, but there's none of the highlighting or the links to other places:

https://gfycat.com/elaboratewatchfulbichonfrise

So, I'm kind of at an impasse. Does anyone know how to upload an interactive GIF to the web, while still being interactive?