@zhenyi But you can get the prompt for the 6-digit pin by clicking on the toolbar button for the extension, as it says in the message (i.e. not on the popup)
@mwichary On duplicated keys: are you aware of the Taipo layout, which is fully mirrored (and inspired by a rhythm game)? The idea is that you alternate between left and right hands during typing. https://inkeys.wiki/en/keymaps/taipo
taipo
A (primarily) two-handed layout focused on consistency, rhythm, and generality