This is currently not possible, and it's not a bug. Your best solution is to reassign the gestures for the add-on until such functionality is possible. I don't even know why the add-on author didn't use shortcuts with the NVDA modifier key as opposed to Shift+F11, Shift+F12 and F12. Doing it this way will ensure that the shortcuts won't conflict with those used by application.
I assigned mine to Alt+NVDA+Up and Down Arrow for the speech history, and NVDA+Alt+Period to copy the last spoken phrase.
