I have been excited by this AP. However on reading the first book, I was struck that Talmandor's Bounty is infested by intelligent humanoids.
The Grindyylows can be understood as they are not likely to come on shore and trouble the colony. However I think the monkey goblins and choker break the deserted colony feel.
So I am replacing them with animal. As a side issue the 1/2 CR animals appear a lot weaker then the monkey goblins. Yet another example that CR is more art then science
I'm going big with my changes. I'm changing the entire mechanics. I'll be using the Genesys system by FFG. And who knows what of the story could change during the course of the campaign based on PC actions.
We switched it to a kingdom-building game, which is a big change especially in pacing. I also sorted out the NPC factions more (modules 1 and 2 are not really clear who belongs to Ochymua and who belongs to Onthooth) and developed some backstory for the invisible stalkers and skum (where did they come from? Are there "feral" stalkers and skum around?) I added some named clans of sahuagin too.
I plan bigger changes later: in particular, I want the lich in #5 to be an active enemy, and plan for him to launch a war against the peoples of the sea, which the PCs will be dragged into by their locathah allies. I envision an arc in which the PCs investigate an undead-wrecked seafolk village and work out what's going on, then trace the evil to its source. I'd like to build him up as much more of a serious bad guy.
Ideally, the PCs' war with the lich will be what gives Ochymua a chance to get in there and get what it needs. In the mainline, for a super manipulative master schemer Ochymua doesn't actually get to do very much, and what it does do is not that sensible.
Well... I haven't started yet, in fact another DM is still mid-way through their campaign, but I'm thinking of running this while making extensive changes.
Some changes are pure setting based - I'm using my homebrew world, so some things are out. The main change (and its really just at the start of the planning stage) is that this will take place on the moon. Help and support will be even farther away.
Aberrations will largely be replaced with draconic creatures, and I intend on largely replacing the underwater aspects with land based ones.
I've just started re-reading the path and haven't even started with notes yet, but based on the campaign outline I can make this work with a whole new skin.