[parmas]

First running pre-turbo with intercooler, in theory, it will not gain any IAT drop in temps.

Although with pre-turbo spool up time should be increased not decreased.

Did you test the setup on dyno or on street? If yes do a dyno map with and without water injection and compare maps. Do not care about bhp and torque since with water injection you should see a drop in power and torque because tuning would be needed.

Please post some pictures of the setup of the pre-turbo and engine bay..