I noticed you already replaced encoded spaces with real spaces. SVG data URIs could be a little more optimized by replacing some encoded characters as suggested by the article: %3D, %3A, %2F and maybe %22.
These optimizations still provide a very decent browser support (IE 9+).
While working on data URI with SVG, I stumbled upon this article: https://codepen.io/tigt/post/optimizing-svgs-in-data-uris
I noticed you already replaced encoded spaces with real spaces. SVG data URIs could be a little more optimized by replacing some encoded characters as suggested by the article:
%3D
,%3A
,%2F
and maybe%22
.These optimizations still provide a very decent browser support (IE 9+).
Let me know if I can help.