If you request ECP tuned in from the get go it will run fine. I drove on an ECP enabled tune for a half year prior to getting the Forge Atmo BPV installed.
Enhanced Charge Prediction (ECP). It's essentially running a hybrid MAP and MAF tune to account for the air being vented to the atmosphere when using a atmospheric BOV.
Yeah, I would put in the notes to have ECP enabled when you purchase. If you don't you're going to run rich during venting events because the ECM will be pushing fuel for the air that is no longer there.