ZEITGEIST Changing Pathfinder's version to 1-30 (Epic Levels!)

So, I adore this adventure path, it's easily the best written one I've ever read, and is generally some top tier fiction. If it were ever adapted into long form novel format, I would purchase it in a heartbeat! I would be happy to run through this AP for years to come, but some of my players have found an issue.

I run very roleplay heavy sessions, where time is spent talking amongst the party, and chatting to NPCs. We're currently 2/3rds of the way through book 2, and we've finished our 30th session. While I know people are enjoying themselves for the most part, we can go whole sessions without directly "accomplishing" anything as written in the AP. This is already a very slow paced campaign, and I think this side-effect has exacerbated the issue. To fix this, I'm looking at switching the level scaling back to the original progression speed it was written for, that being, 1-30.

I've found some problems in doing this though. The level of the encounters don't match up to the CR as calculated by Pathfinder, in a way that on surface level seems arbitrary. Now, I don't think that it is because all combats thus far have been fantastically balanced. But I was wondering if there was some formula or process that was gone through in designing the encounters for Pathfinder that took CR into question.

In addition to this question, does anyone have advice for switching the leveling curve over to the e tiers of play? This would have the PCs hitting level 10, 20, and 30 for the end of books 4, 8, and 12 respectively. I know from personal experience Pathfinder begins to break down even once you pass level 11, so how would people recommend keeping the spirit of Zeitgiest alive well into the epic levels, while satisfying the Player's need to keep leveling up?

A side note; I've been recording all of the sessions of my group's trek through Book 2, as we've been playing on Roll20, I'm super excited to share it out with people!

Thank you so much for your time!
Open Book Irony

Well there are no rules (except for a few paragraphs of guidelines in the gm's guide) for past level 30 in pathfinder.

You could adapt 3.5 epic rules but epic magic would be completely broken , you would have to redesign every encounter and it sounds like you are not familiar with high level play so adding this level of complexity would be bad.

You may be tempted to use mythic pathfinder rules to stretch out progression do not the rules as written for mythic are unplayable particularly if you are not familiar or comfortable with high level play.

So you would just be adding 10 extra levels to each PC past lvl 20. This is going to mean rebuilding all the encounters in the entire campaign which , also it would mean that pc's will have access to 9th level spells about 2/3 of the way through the campaign this will totally break the entire campaign , giving people high level spells before the campaign expects it will be a disaster the problem being that in pathfinder a 20th level character is not twice as powerful as a 10th level character more like 10 times more powerful . I believe 4th ed which had the lvl 30 progression claimed to be different but one read though of the players handbook is my only experience before I threw it in the bin.

I think the problems of trying to convert pathfinder to a level 30 system are vastly greater than adjusting your expectations about levelling every few sessions. It seems your group spends more time on RP'ing and discussion (or has much shorter sessions than mine) I expect to get though book 2 in about in 6-8 sessions, so it seems to me that mechanics may not be the main focus of the group.

It also sounds like you have not GM'd many games beyond about lvl 10 and in that case I would be even more careful about committing yourself to big changes in the high level games, I like and run a lot of high level games and I would not want to mess about with rebuilding the endgame and maybe rewriting bits of the system. In this AP many of the 'big bads' and indeed even some encounters in book 2 are not designed really by the pathfinder rules which makes the already unreliable CR system even less useful as a guide and makes rebuilding the high level enounters hard, I would not want to make big changes to the Voice of Rot , as it is given that my players are skilled at making powerful characters I may have to fiddle with his hp , ac , saves and to hit scores but at least I won't have to to a total rebuild .
Another thought about CR is that in book 2 a lot of the fights are one fight per day, this lets pc's nova and use all their abilities when normally they would have to husband them , that throws of CR badly as CR is designed for 4-5 fights and attrition of pc resources