I built this over the weekend because browser support is a moving feast. I'd find myself exploring SVG, thinking "That's great - I can't wait to use it." And then not noticing that there is basically 95% support now.
Feature request: Allow user to set minimum required browser support more granularly, e.g. 'IE>9 && 90%', kind of like how https://github.com/postcss/autoprefixer does