Speaking of entries to Jorgenfist... I'm just wrapping up The Hook Mountain Massacre now and thinking about how my group is likely to handle Mokmurian and Jorgenfist. They've got a scryer subschool wizard and setting aside the question of whether he'll want to pre-empt Teraktinus' assult on Sandpoint by scrying on the giant and launching a teleport-enabled surprise attack on the raiding party before it's in position, I'm thinking ahead to what other scry-and-teleport tactics he might employ.
Following the raid on Sandpoint, the PCs can interrogate one of the stone giants and should have a good idea that Mokmurian is, if not the "boss monster" of Fortress of the Stone Giants, at the very least a major mover-and-shaked at Jorgenfist and the architect of the raid on Sandpoint. For scrying purposes they have certainly heard of him (save DC +5, modified to 0 by the Scrying Adept supernatural ability of the divination arcane school) and have one of his possessions (the missive he wrote to Barl Breakbones, found at the end of THMM) which imposes a further -4 penalty on his saving throws, reducing his Will save of +15 to an effective +11 vs. a save DC that will be at least 20 at that stage in the campaign and may well be a point or two higher. It's quite possible that the PCs' very first attempt at scrying will succeed, and even if it doesn't, Mokmurian can't reliably make his saves.
Yes, he's a level 11 wizard and a CR 15 creature, but if the PCs use scrying and then teleport, they'll catch him without his buff spells active and based on past experience will take him apart on action economy alone.
So: what defences does (or might) Mokmurian have against scrying and/or teleport, and failing that, what are the implications of the PCs, armed with knowledge of the villain's name at the very start of the module, using those spells to confront him immediately and essentially skip past the entire module?
I don't think it would be unreasonable for an accomplished mage, which Mokmurian certainly is, to have his quarters protected with a Mage's Private Sanctum spell. He also has the capacity to make the effect permanent. Whilst on his travels he could utilise the spell Non Detection, it all depends on how aware he is of your PCs abilities and perhaps how paranoid he is.