Avoid writing huge, long rambling comments and try to simplify your arguments to less than 100 words. You may find the fault, and the fix, becomes obvious.
Start with trying to refute "The python2 executable still functions correctly as does all other code you have that relies on python2" without referencing anything specific to your build practices.
> This is also hilarious since you had to scrape the bottom of the barrel to find the only instances of "non backwards compatible" features in JS/HTML, an environment notorious for backwards compatibility. Also, `alert` may still stay in.
Those where the first that came to mind. There are many others, and many more if you widen it to server-side JS.