Answer 1

Paul Caron In that case, you probably need testers (someone with an older device) to test your code. Actually, most of the browsers today support ES6, which makes you worry less about making it work on ES6-unsupported browsers. (You have already added Babel to your code, so you need not worry, it MUST work :) Someone, for whom it won't work, will prolly notify you by posting a comment on your code or in this thread (like ᠌ ᠌ ᠌᠌ ᠌ ᠌ did!)

Answer 2

ES6 is supported on my device (my web browser supports it), perhaps it works smoothly here. Could not test it out, though I think this thread might be helpful to you (somehow?):

https://www.sololearn.com/Discuss/1220172/?ref=app

Answer 3

I've just checked it using an old and laggy device which doesn't support ES6 at all and which I don't use very often. I get this:

Uncaught ReferenceError: Symbol is not defined
Line 338

//btw, I don't find Symbol in line 338

Answer 4

Not sure if I usually have issues with es6, but I can tell you that I see it. (Super nifty!) It just takes a minute to load.