[Question] Toggle intl.accept_languages

[Yaron10]

Hello,

Thank you for "Quick Accept-Language Switcher". I find it useful and I appreciate your work.

I've recently upgraded from FF 52 to FF 64 and I'm not familiar with the new API.
I used to have a toolbar button toggling intl.accept_languages between two languages.
I understand this is not possible in FF 64, correct?

May I ask if creating an extension toggling requestHeaders between two predefined languages would be a lot of trouble for you?
(I'm using the unbranded version and I could try it without AMO).

Best regards.