Polar is right again. I’ve done a bit of reading and talking to tuners about water injection and yes you can advance the timing and get noticeably more torque.
But, what happens if there is a failure of water supply? Bang!
There may be ways around this with sensors and detectors that switch over to a safer map when a fault is detected. A reflash or piggy-back can not do this, y’d need a chip that can hold at least 2 maps, motec or autronics maybe. Comments anyone?