Why are the SVG tiles specified to 599.99999999 instead of 600 or something? I think a SVGO optimizations run would reduce the size of the assets a tad.
Didn't get a chance to look at your source.
My svg handling was very much "learn as I go". An earlier version even had circles instead of hexagons because they're simpler to do. There's a cool playthrough video of that version: https://www.youtube.com/watch?v=vlpPr485NUY