When Hook is called with shift + cmd + space, the shortcut displayed at the bottom of the window indicates that ^t will open the submenu of available actions, which works with the letter t on a QWERTY-layout keyboard but not with the ^t on the Dvorak layout.
Welcome to the forum, @marlowe, and thanks for pointing that out. The work-around is to use ⌃k (which is the physical
T key on US keyboard). We will look into it.
Thanks for posting the question and answer both! I use Dvorak and was having the same issue. I should know by now to check this kind of thing, but I always forget.