Mind, Mysteries of Westgate still requires online activation after each installation, even though it's unlimited now.
Oddly enough if you buy the NWN Complete Collection from GG you don't get an activation key for Mysteries of Westgate. Do you think that's a mistake or maybe the Complete Collection is different? I got keys for NWN, Shadows of Undrentide, Hordes of the Underdark, NWN2, Mask of the Betrayer, and Storm of Zehir only.
Is there any multiplayer-part in it so you need a key for online-play? I also bought the bundle, installed it and tested it with starting Mysteries of Westgate. It started without a problem, but I didn't played it. The only problem I found so far is is the silverface bug from NWN1, which can be solved by reinstalling the patch 1.69.Like gogs release except kingmaker all other premium modules are missing, but there is no problem to download them for free.
Btw, except the serial numbers there was nothing visible regarding drm. Unfortunately I forgot to disable internet while installing it to see if there going on something in the background.