shift:breaks_caps should kick on press, not release #780
Description
The option shift:breaks_caps is expected to break Caps on Shift press, but due to limitations in the XKB protocol it cannot be achieved, leading to unexpected behavior.
This is explained in details in this old xkeyboard-config issue.
This is similar to #372, but it deserves it own issue (current SetMods vs `LockMods there).