Just when I thought I'd heard it all from this pedal, changing to square wave you can get some pitchy burst noises and major/minor key autoriffs! hold mode, well i wont ruin it for you but there's much fun to be had!
I don't have a camera right now but it's very simple. open the back of the pedal, you can solder a jumper wire the center lug of the speed to the left lug of the depth pot. If you're brave I think it might be useful to wire a new pot for this connection instead of a jumper because I tried a few resistor values and it makes different shapes between square and triangle, sawish.
Also, for the official digitech schematic in the archives, the company may have mislabeled the lfo part, it seems to be tl022s instead insead of tl062(unless they did something sneaky)