Any chips that re-program the shift paddles?
 

I'm curious if any of the ECU tunes out there converts the left paddle into a proper downshift, eliminating the need to use the buttons. I'm not a fan of the buttons and not sure how I would enjoy using them.

You can get the wiring diagram in the FSM - Part 13, Section H1.

Both down switches as wired from ground, in parallel, through a resistor to a terminal on the TCM.
Both up switches are also wired from ground, in parallel, through a resistor to the same terminal on the TCM.

So, An ECU modification can NOT alter the way the switches work. To get the effact you desire, you would need to rewire the up switches (and possibly modify the down switches).