Is it possible to add some URLs in a block list where the webextension should be disabled ?

Hey Dave,

Disabling from the context menu isn't ideal because I'll have to do it every time I restart Firefox.
I'd prefer not having to be in a private window because I want to be 100% sure that my dev is working correctly in a non-private one.
I know there's this possibility to disable all the webexts in adding localhost in the pref extensions.webextensions.restrictedDomains (in about:config) but I'd like to be sure that its default value is correctly updated when Firefox is (and I use nightly).
So really I'd prefer having a list of urls I can block permanently without having to think about one of the workarounds you proposed.
FYI, since few days, I can see in my console:

when browsing for example https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toSpliced.
I've this exception too with my local server which means that it can interact with my own stuff and I'd prefer not (especially when profiling).

Anyway thank you very much for your fast answer, I really appreciate.

Calixte