I just got the update with the new private mode toggle on the homepage in Firefox Beta and I gotta say... as a right handed person: Not quite my favorite UI change.
Instead of having the toggle in the top right corner, which, while not a good position, since its far away from the bottom of the screen, where my thumbs usually are, it was at least reachable when regrabbing the phone or using my index finger. Now there's a... book button with the left page filled out and an empty right page.
Tapping it reveals: That's where the News will go in future versions, presumably. Since I don't care for news on my homepage and I don't like buttons I never use cluttering the screen, I looked for a way to disable the news button, but the normal settings don't provide one. Since the news themselves are missing, I'm hoping that that's because I'm on the beta branch and once this feature gets refined, there will be a way to remove the button, just like other things on the homepage that I don't use. Thank you that that's already possible.
Tapping the new private mode button in the top left corner of the screen takes you to the private mode and moves the private mode toggle... back to the top right of the screen? Now that's odd. That's almost like moving a checkbox to the other side of an option once you click it. I really don't see a purpose behind having the private mode toggle flip which side of the screen it's on when tapped. If a user now quickly wants to check if there still are private tabs open and leave, if there are none, this action now requires tapping opposite corners of the screen, instead of just the same place twice.
Also, having an important feature such as the private mode toggle in the corner furthest away from right handed users that use their thumbs on the bottom of the screen to operate their phone, makes it quite a chore to use, a bit like the usability nightmare that is Discord on phones.
Since the tab switch menu got redesigned and also moved the private mode tab to the top left, I've been using the private mode toggle on the homepage and tapping and holding the tab button a lot more. Now the private mode toggle is also getting less usable, which is not great, since tapping and holding the tab button and precisely hitting the correct option without closing the current tab or opening the wrong kind of tab does work, but it could just be tapping a button that is easily reachable with a thumb or at least the index finger, if putting the private mode toggle on the bottom right, when using the bottom address bar is not an option.
While I'm sure left handed people are happy about having the private mode toggle in a corner that's easier to reach for them, it would be pretty great if the position of the private mode toggle was configurable to suit both left and right handed people. Further, it would also be really, really great, if the private mode toggle moved near the address bar, so bottom address bar users could also have easy access to said toggle, just like top address bar users already have.
