I will say that it depends on your SA and the dealer you're working with.
Some will rat you out and others don't care. I would however, if anything breaks or fails put back the old ones when doing more serious work such as turbos or anything exhaust related.
As for DD they're are the DP fix and code suppression so having DP's will give you that extra little kick in the pants and put less stress on your turbo system.
Go to an Indy shop for any maintenance if your worried about work being done and when something serious happens swap out the mods.