Let me start by admitting that I am "one of those people". I really dislike havens, with heavy emphasis on the word 'really'. I am also disappointed in the changes to how Endgame races are achieved.
My reasons for this are many, but let me present a few. I have spoilered my discussion parts to make it a bit more TLDR-friendly. Feel free to comment with your own ideas or poke holes in this one. I just thought I'd throw it out there.
1. The lore connected to them is not very consistent, and it can be difficult to try to justify certain things connected to them.
It's part of your mind, something of a "Sherlock Holmian" mind palace, but you can invite others in person, sort of like a virtual group chatroom in a fantasy setting? Fantasy games are good that way, as they can break free from conventional stuff, but part of it makes me feel like it's a bit of a stretch, like when you go in there and come out again with physical items created inside your mind. (Enchantment rooms, forges and libraries are all possible to set up in a haven, for example)
2. Havens do not promote spontaneous interaction, despite the addition of shells that can be shouted at or wrenched.
Sure, it is nice to have a place to retreat to for a while, and people can reach you in other ways, but most people have taken to returning to their havens in remote or more inaccessible locations to be left alone. I'd say that is what havens are there for. You want some peace and quiet? Go relax in your mind, daydream for a bit, meditate, and then return all fresh and stuff.
Things in this game should promote interaction, not provide more ways to isolate. Sure, there should be ways for people to step away from the public eye, but perhaps in a way that makes more sense than inviting someone else into their brain?
3. Haven points keep piling up, without giving people a chance to use them for something that feels important.
Expanding on a haven's room count, when it's an isolated area, can feel pointless. However, when you have all the racial skills available, what else should you be doing with your points?
I have no idea how to fix havens, other than to suggest to remove them or turn them into single rooms for personal escape.
Let's say you want to create an Ice Queen of the North, so when you become Endgame, you choose Ice as your preference. This means that as you progress and earn "haven points", you are able to choose from ice-related flavor stuff, to further promote your change towards regal status in the north.
The "Flavor List" would be similar to the "Raceskill List" we see today, only with messages and flavor things added. For example, you could get access to certain premote things, like "ICESNAP", which shows as you snapping your fingers and creating a spark of snowflakes (while "FIRESNAP" would show as a spark of fire instead, and "WATERFLICK" would, annoyingly, flick a few drops of water in someone's direction). It could also give access to other kinds of flavor, like a skill called "CHILL", which would make the room feel a bit colder for a short while.
I am fully aware that a lot of these things are used for trade and economy, but I do believe it would make sense to add some of this as part of the progression system. Naturally, there are probably a lot more things to add, but I thought I would suggest something.
We currently have three generic endgame races in the game:
Yeleni - the Hollow Form of Tekal being filled up with life essence.
Azudim - the Hollow Form of Tekal being filled up with death essence.
Idreth - the individual's own reforming of the Hollow Form to transcend the mortal shell.
Without Divine interaction, there feels like there's no reason behind the choices of the various forms.
Why even have three races if there's no real difference in how they can be obtained? The first two races made a little more sense back when one had to approach a deity to be turned into these new races. You'd generally get some kind of quest, and when completing it, the deity would grant some of Their essence for you to transcend into this elevated form. Still, there was the difficulty in interpreting where Undeath fit into it all, but that was something that could be roleplayed out to make sense. Then came the l introduction of the Idreth, which was meant to negate the requirement of Divine interaction. It gave people the option of just getting to Endgame without the fuss.
The removal of the requirement for Divine interaction made the connection to essense feel irrelevant, and the hard work others had put in to gain these by questing for their respective Divine's attention and favor was somehow lost in the past. Those quests made for excellent character building, and this is, after all, a Roleplaying game, so character development should be promoted.
Add in separate Endgame races for the different deities, that people can aspire towards.
Make them connected to their deity, and change/shift depending on Their stance. Allow said deity to rip them apart if they no longer deserve said form, making it necessary for them to reform as an ordinary Idreth when returning from the Halls. It should be seen as a privilege, something obtained after hard work has been put in.
It doesn't have to be much, or have a lot of stuff added to it, even though that's certainly something that can be added and should be possible. Look at how Chiav works, which is a good example of what could be accomplished that adds a lot of flavor for those who are devoted to a certain Divine.