Just finished work for today 
Ok, I have little time right now, but perhaps you cn figure it out how the binding stuff works.
DoublePress.cantabileSong (42.4 KB)
SecondFunction.cantabileSong (38.3 KB)
The main idea behind the doublepress functionality is, to enable a certain midi routing for an amount of time. When you press the same button a second time within that time range, it will get routed through the activated midi routing but on a different midi channel. The rest should be clear.
The idea behind the modifier key is to enable a midi routing with a unique target midi channel while the modifier key is pressed. That lets you choose different actions for one button which gets pressed while holding down the modifier key.
Another nice feature of this is that you can perform two actions simultaneously while holding down two modifier keys.
If you have any further questions, feel free to ask.
Greetings, Tom