I still try ctrl+shift+b every time I want to open bookmarks library because that just makes sense and pretty often tap backspace when I'm sitting besides someone else trying to figure out a way around an unknown website to quickly move back in histo...
additionally I do kinda understand why you changed some things to be like Chromium but also would prefer to have a predefined Firefox set that has backspace and ctrl+shift+b working as expected without the need to alter them separately
I'm pretty sure the tab bar popped up when scaling was set to a certain value even before and that's the main reason I opted for a slightly less dense UI, to avoid the tab bar, so it certainly needs to be easy to disable
regarding links to the outside of the app: make sure to pass them to the OS, don't keep them trapped inside of one browseruser is allowed to choose the default handler however they like and one of the big issues with Chromium PWA is the fact they kee...
