Hmm, this is very neat and elegant! But how well is svg (or data:) favicons supported in random non-strictly-browser context, like password managers, or some link aggregator/bookmarking style sites or apps?
You can download the PNG version to create favicon for older browsers, but it's something we'll cover in the next version. There would be a "Download All" option with all required PNG sizes, and a sample html file with higher priority for the SVG version. So modern browsers would use the SVG version, and old browsers uses the PNG files.
You can check the browser supports on https://caniuse.com/link-icon-svg
You can download the PNG version to create favicon for older browsers, but it's something we'll cover in the next version. There would be a "Download All" option with all required PNG sizes, and a sample html file with higher priority for the SVG version. So modern browsers would use the SVG version, and old browsers uses the PNG files.