It has been a core feature since v50, albeit with less feature than the addon. It's still disabled by default, just need to toggle the following configs to enab

It has been a core feature since v50, albeit with less feature than the addon. It's still disabled by default, just need to toggle the following configs to enable it: privacy.userContext.enabled;true privacy.userContext.ui.enabled;true privacy.userContext.longPressBehavior;2 The last config is so that you can open a new container tab by long-pressing the new tab button.