The stock computer doesn't know the car is under boost and of course doesn't have a map table for it. The ECU still thinks your running WOT at X rpm with zero vacuum so its going to reference its max table for fuel output for a NA car.
I would guess that toyota wouldn't push the injectors anywhere near 100% when the driver mashes the throttle and the car still thinks its NA so there is nothing to tell the injectors to go beyond the factory cycle. In reality this probably means toyota has the injectors pushing no higher than an 80-85% cycle and would be no different than me driving my car now as far as injector duty cycle. Plus most drivers are only at full throttle for a few seconds at a time. Even a quarter mile run should only last 15 seconds I would hope.
I agree that you can only push so much fuel to tiny injectors until they stall and drop off. My plan is to put together a simple low boost and low budget 5sfte. Since I have all the part to build a 5sfte with an FMU I just need to get off my lazy butt and start wrenching.
I'm sorry if I've turned this thread into junkyard wars tuning but arm chair tuning is kinda fun.
Redstar sorry about the
I misread your post at first and did a quick edit.