The TotalSpaces implementation of trackpad swipes works great: it intercepts the system command, then does its own thing, changing the space with TotalSpaces. Then in Mission Control it passes through the system commands so Mission Control swipes still work as expected. So far so good. Better than anything that can be achieved with BetterTouchTool.
But, if the number of columns in TotalSpaces > 1 then up/down swipes change space, so you can't enter Mission Control with the Trackpad, which I don't like (I can already reach any space with left/right swipes and circulation enabled).
So I think this would be a good feature, and also probably easy to implement.
Thanks for reading.