I discovered this a few days ago, and have already used it a few times. Seems to be a lot easier to use than other generators. The only problem I've had is when you add prefixes to the grid names, and then create a CodePen, the prefixes don't show up in the CodePen.
MDN's compat chart doesn't make clear if Edge supports this or not but manual experimentation suggests not although trimRight is supported so a possible polyfill. I filed a bug against Edge just now.
Microsoft Edge 44.17763.1.0
Object doesn't support property or method 'trimEnd'
: function createTemplateArr(number) { return '1fr ' .repeat(number) .trimEnd() .split(' ') }
MDN's compat chart doesn't make clear if Edge supports this or not but manual experimentation suggests not although trimRight is supported so a possible polyfill. I filed a bug against Edge just now.
Firefox 60 ESR