2010 FLHP does not come with cruise control. You cannot purchase a factory cruise module and just plug it in because the wiring harness is different.

So...

Could a standard FLHR wiring harness from the same year be swapped in?
If so, what would it take to do it?(ballpark issues)
pros/cons?

There are some pretty pricey kits out there that make cruise possible, but they all use their own funky modded buttons. If I were to attempt adding cruise, I'd rather use a factory option. It just seems safer.

 

It is possible. My f-i-l added cruise to his police bike as well as added civilian controls but kept the bikes harness. I remember because I had to pick up a wiring schematic for the police model from my dealer and take it to him. He cut and spliced to make work.
I assume swapping harnesses would be plug and play but a major pia.
Just throwing it out there. Good luck.

 

I'd love to pick his brain. What year was his?

 

2012. The mechanic at the Harley shop in Tyler, Tx was a lot of help. I believe he can even make a harness now after they completed his. May be worth a phone call.
I'd gladly give you the fil s number but he is a club guy and stays on the road ALL the time!