Run modena a select some toggle button. Use left-right keys to traverse. You will see the following cases:

1) When toggle button is selected and focused, both focus and selection moves
2) When focusing out of toggle group to another toggle group, the first button is *NOT* selected, just focused
3) Using TAB to focus to the middle button and then using arrow keys uses the focused button as a reference for changing both focus and selection. I.e. when B1 is selected, B2 is focused, moving with arrow key to B3 makes selection to jump over the B2.

This should be more consistent. The primary cause is the introduction of selection change with arrow keys as requested in RT-23528.

My idea is to "revert" RT-23528 when 2D traversal is ON (for embedded). For desktop, arrow keys would not do any traversal from toggle buttons, only selection would be considered. That means in case #2 above, it wouldn't be possible to go out of toggle group by arrow keys. In case #3, B2 would be selected, ignoring the current focus.