ok, I think I got it (I too want to remove both the QR things).
try latest 3.3.3.
In
settings, toolbar, configure address bar, there is an option
show shortcuts button.

- shortcuts.GIF (15.22 KiB) 查看 1468 次
select and relaunch the browser
now there is a shortcut button you can choose various functions. You can also add your own custom shortcuts.
BUT, I also see no way to turn each one off/on. It also does nothing for the right click context menu QR function.
If we disable the
show shortcuts button, there is a possibility the QR code button may never appear. Since, as you said, it doesn't always appear, we can run it for a while to see if it does. So far, so good.
Catsxp - don't care about the QR code customization....he was asking for option to remove it from the address bar AND to remove
create QR code in the right-click context menu. Looks like there is a way that it's removed, if you just turn off the
show shortcuts button.