Hah. Thanks. I was stopping by this thread again to post exactly that. I have to say that config option was not obvious. After scrolling through about:config and filtering only the modified list I still couldn't find it. I finally backed up prefs.js, toggled it, then pulled a diff.

And, I needed the config entry because I couldn't find any gui option to opt out of it on mobile.

So that means it's on but can't be disabled without using this hacking around? That's not cool :(

I've used it for years and have not had many crashes so there is no real need for 'caution'. I also run Debian Sid on laptops, another 'unstable' system which is remarkably stable despite its moniker. If these were relatively new systems/programs there would be more churn but at this stage of their development the changes made tend to more gradual and less crash-prone.