That is really cool. Is it a thing I can use now, or in 2020?
You can use it now, just fork the Codepen.
Defs ready to go! I used this technique on https://bigfish.tv/ way back in 2015!
I have yet to find a solid SVG animation tool. SnapSVG is a nice library, but a powerful wizzywig for designers seems like a market gap right now.
Native MacOS app for animating and exporting SVGs would be great
https://github.com/bodymovin/bodymovin With this you can work in AE and export to "svg/canvas/html + js"