Thanks for the help. I'm using a cheap ELM unit with Torque Pro, not many options for injector pulse widths.
Today I whipped out the coils, plugs and injectors. All looked identical. Checked the tops of the pistons. Cyl 1 & 3 have a layer of carbon deposit. Cyl 2 is very clean, indicating a hot burn to me. Both the injectors looked identical.
I've swapped injector 2 & 3 to see if the misfire moves / the top of the piston cleans up.
Not sure the car has been trying to compensate with extending the duty cycle but would be cool to see that sort of info.