2008 WRX EJ20X swap help

Hello guys, I currently own a 2008 Narrow body Stink Eye WRX, and I'm doing an EJ20X swap on it because my EJ255 gave out about 3mnths ago. I've looked on some other forums for help as I know that the EJ20X has a twin scroll turbo, dual AVCS, and (correct me if I'm wrong) a compression ratio of 9:5:1. Some people say that if I just leave the exhaust cam solenoids disconnected that it'll work and that I wont lose much power, others say I need to tune it and tune out the exhaust cams, and for the compression difference and twin scroll. I would appreciate some help and further input on this, my knowledge with Subaru's isn't that great. Any help is tremendously appreciated.