Interesting point but unfortunately there is nothing I can do. I have to use this API to support the people who use this feature (#350 and #368). We would have to open a change request at Mozilla to allow extension to use this feature and let the user disable it.
PS: this feature should be also available in Firefox 67.
When you right click on a link, there is an annoying “Open Link in New Container Tab”, which on its own has a sub-menu with Personal, Work, Banking & Shopping. Quite annoying. For now, I will use this hack until this get resolved (if…).
Someone made a patch 7 months ago, but nothing happened since then for no apparent reason. Maybe @kkapsner can poke the right people there or take matters into his own hands, to speed up the process. 😅 I've upvoted the tickets ages ago, since I've been 'suffering' from this issue when Cookie AutoDelete introduced Container support..
@concatime Thanks for the hint of the userChrome.css entry, haven't thought about the ability to hide that annoying context menu option that way before.