It looks like your water might be a bit much at high RPM. I think it will like it better with the gain a bit less, as you have planned.

Do you have a wideband on the car you can datalog as well? This is probably your best tool you will have along with knock readings. It's not impossible but is a bit tough doing it the way you are.

I'm sorry, but I don't know the particulars of your ECU, all I can offer is general help based AFR's, meth mixtures and system setup. I'm glad to help as much as possible, so if there is something I can help with please ask.