The stock 450s might have been good enough.
Around -30% will work fine for the low throttle and idle, but in the high throttle settings you usually have to go a lot farther negative. If it doesn't flow much air, though then you might be fine. On a bigger turbo with 660-680s on a 2G you often enough up being in the -42% to -50% range on the AFC. The main drawback to going so far negative on the AFC is that it puts the ECU into the wrong airflow maps and often trys to run too much timing, which results in knock. 2Gs don't run nearly as much timing as a 1G, so that might help a little, and without a DSMLink to see if it's knocking or not you won't know how much it is retarding timing, so you can instead just pretend it's fine.
It should run fine though, I hope you have a FMIC for that much boost.