There is chrome://geckoview/content/config.xhtml but many options shown there are nonfunctional. The relevant option is listed but I'm not sure if setting it to false has any effect.

Edit: Just found out that on that link above, you can set general.aboutConfig.enable to true to enable about.config.

It looks like the xml page and the about.config one are the same, as the modifications I made are synced.

Thank you so much for that! I was missing the ability to configure a very important option for me in Stable (layout.css.prefers-color-scheme.content-override), but couldn't keep using Nightly because of its instability... You're a lifesaver!

Use Mull[1].

It has sane defaults and about:config is accessible.

[1] https://f-droid.org/packages/us.spotco.fennec_dos/

I just found this setting in mobile, but I don't know if it's the same feature: Settings > Data Collection > Marketing

I don't think so. I already had the setting visible in the UI disabled, but the thing in about:config was still on.

about:config works on Android Firefox nightly. Just checked.

hm, should I use the stable version, but be tracked,

or should I use Nightly, and risk crashes and catastrophic loss of data

choices, choices

I believe the unbranded Firefox build on F-Droid (called Fennec) enabled it even on stable releases.

or use an unbranded fork that has about:config enabled

amazing, the one app that has access to everything that matters in your digital life, and you'd be willing to use a non-standard source?

The standard source comes with malware, and the one big alternative comes with malware. Such is the state of the tech industry (even nonprofits) in 2024. Random individuals like Raymond Hill are far more trustworthy than large organizations.