How to customize user.js in Qubes DispVM?

There are two issues I have with default settings of Whonix’s TB on Qubes:

  • the language notification says it set English, but it changes fingerprint (Screen size) until you close it, and doing so every time is annoying.
  • security setting is Standard, Safest would be better.

Both can probably be fixed with a custom user.js but what is the best way to change it so it works in DispVMs?

Okay, seems like I don’t wanna do this after all: /wiki/Qubes/Disposables#Disposable_Templates

but I still think noJS would be better than JS, it may change fingerprint but then again websites will have easier time fingerprinting you when you use JS.

Duplicate of How do I customise Tor Browser in a Whonix TemplateBased DVM in Qubes-Whonix

Disposable Template Customization