Honestly using modern web technology (Babel, PostCSS, etc.) makes it pretty easy to maintain IE11 support without TOO much effort and there aren't that many fea

Honestly using modern web technology (Babel, PostCSS, etc.) makes it pretty easy to maintain IE11 support without TOO much effort and there aren't that many features you absolutely can't use (CSS grid is probably the most painful missing feature). That being said, our company is deprecating IE11 support in October and I already have the PRs ready to rip out some of the code that bloats our JS/CSS with polyfills.