Even with the ATT and the kind of fuel I am able to command with constant high boost the IATs get high. If not going to be towing something heavy often it will never be a problem. Water injection would do the same thing and more than an I/C but then you add moving electrical parts and potential to damage the engine with too much water or methanol or just some water leaking into intake when not running and pooling instead of the atomized mist when under pressure. Thats why you have to use good nozzles and solenoids and stuff, or a good system. I/C is kind of set it and forget it, dont have to continue feeding it and no real operating costs.
Not necessary to run an I/C with anything, just good for pursuit of reliable power.
. 
