There are header meta tags that you can put in your HTML to enable PWA-like functionality. With them you can do things like enable full screen and change the status bar style. However, they are not standardized and are far less convenient than the Web Manifest.
Wow, that's impressive!
Handlebars is nice. It has lots of features and is really popular. I only recently started using it and everytime I was wondering how to do something there was already a thread on stackoverflow with a working solution.
You can never have too much ice cream!
I highly recommend this extension for connecting the VSCode debugger with Chrome's devtools.