How do Firefox Add-ons affect my browser fingerprint?

Questions
1

I often see people stating that Firefox Add-ons will influence browser fingerprint, so shouldn’t enable any extensions in Tor Browser (even including UBO). There are also claims that some extensions, such as Dark Reader, may still affect the browser fingerprint when “enabled but not activated” (for instance, when the dark mode is not turned on).

To clarify potential ambiguities due to my non-native English, I’ve defined a few verbs:

  1. Enabled: This refers to enabling the extension in Firefox’s “Manage Add-ons” interface without actually using its functions, such as enabling a translation tool or the dark mode of Dark Reader.

  2. Activated: This refers to manually turning on the primary feature of the software, such as the translation function or the dark mode.

I acquired DOM, canvasDataURL, and other data by injecting a script I wrote into the browser console. I compared two extensions I commonly use: TWP (Translate Web Page) and Dark Reader, checking how they change under both conditions of being enabled but not activated and being enabled and activated.

Default: dom totalElements: 2347, scripts: 5, iframes, embeds, mozExtensionScripts not detected, canvasDataURL: original

TWP Add-on enabled but not activated: dom totalElements: 2347, scripts: 5, iframes, embeds, mozExtensionScripts not detected

TWP Add-on enabled and activated: dom totalElements: 2348, scripts: 5, iframes, embeds, mozExtensionScripts not detected

Dark Reader Add-on enabled but not activated: dom totalElements: 2348, scripts: 5, iframes, embeds, mozExtensionScripts not detected

Dark Reader Add-on enabled and activated: dom totalElements: 2370, scripts: 5, iframes, embeds, mozExtensionScripts not detected

From this test, it appears that besides Dark Reader enabled, enabling the other extensions does not significantly impact the fingerprint. What do you think? Is there anyone who understands this in more detail? Do these extensions affect browser fingerprints when they are enabled but not activated? And how much impact do extensions like translation tools and dark mode tools have on the fingerprint?

2

I’d first like to know if there’s a reason you’re looking at browser fingerprinting in such a pedantic manner? Also, what are you trying to gather/accomplish by understanding this as you want? I’m curious.