I just finished installing one of these in my truck yesterday by myself...man it is not easy holding these up with only one person. In regards to the bypass switch, what I have been wiring tonight is a relay going to the solenoid and using the governor as the ground for a relay with a on/off push button switch between the switched hot for the relay. That way I can turn on/off the OD when I want above 28mph and it will automatically turn the OD off when I slow below 28 mph so I don't accidentally take off in OD from a stop. I made a quick drawing of it:
Let me know what you think