Hey, thanks for creating an amazing piece of software! I have some issues using the keyboard and want to create multiple gestures for my (5 button) mouse. I'd like one key to act as a modifier key (let's say fn) so that when I press other buttons on the mouse while that's pressed, they can trigger different actions (such as back/forward on my browser) without me having to press anything on the keyboard.
I've tried setting this up with:
- Mouse Button 4 Down -> Fn Key Down
- Mouse Button 4 Up -> Fn Key Up
- Then setting the fn key modifier on my other mouse triggers (fn + Mouse Button 3)
Unfortunately this doesn't work consistently.
I'd also like to set up a gesture for cmd-tab:
- Hold a mouse button to act as cmd (or, ideally, click it once to hold cmd-down and then use something else to trigger cmd-up)
- Click another mouse button to act as tab, or just use the scroll wheel.
Please, I'm a huge BTT evangelist and this is by far my most needed feature request 
