Going back to post #8 and post #13 above - do you still believe HTML5/CSS3 is not important? And XC should continue to heavily rely on HTML4/CSS2 and JS?
See this -
https://forum.x-cart.com/showthread.php?t=73008
HTML5/CSS3 compliant cart is a must. No HTML4, CSS2. tons of js code, etc is necessary. There is a lot HTML5 can do on its own.
I myself have replaced many js files and lines of code on my site converting it all to HTML5/CSS3 - using latest XC 4.6.x. It took a lot of time and effort but it is not impossible.
If you are to support XC4 for the next 5 years, as it was said and promised, you need to get next XC4 version released completely on HTML5/CSS3. The existing XC4 customer base will quickly disappear - who needs old outdated patch over patch over patch cart full of features? Features which cannot be used or need constant fix?
Just saying....