Looking at the operational and installation instructions, I think there may be challenges installing the switch. I am pretty savvy at electrics and believe that the switch can be made to work on most wiper motors but the actual connections and installation might be tricky. It seems to me that the available existing wires would have their connectors cut off and new terminals crimped on.
You need to determine if you have a one or two speed motor, a parking signal wire, and what existing connections are for the back lighting. I am not sure how that lighting is supported by the new switch. It may not be but does have its own light that appears to be dimmable.
Although I am confident that I could figure it out, it could be a complex task if you are not well experienced in how 12 volts boat systems work and are wired. If you do have a washer feature and it is on a separate swish, to move that to the new switch will require disabling the existing switch and relocating some wires to the new switch
If your existing wiper system is one speed, does not automatically park the wiper when turned off and doesn't have a washer function, the only new feature you will get is the intermittent wiping. What I can't answer is where the wiper sits when in intermittent mode if you don't have a park feature and connection on the existing wiper motor.
Maybe the task is simpler than I am making it look but I am trying to identify what roadblocks you might run into.
And yes, your original question on the existing wiring and if anyone has a schematic is noted. That would help. If you can get to the wiper motor and look at the wiring, that would help identify colors and knowing what pins on the existing switch those wires connect to would help identify their function.
If you can identify the make and model of the wiper motor, that might help locate a wiring diagram. I looked up some wiper motor generic schematics and they all supported a parking signal and a two speed motor. That would make the new wiring relatively simple.
It looks like a 'fun' project.