Since you have brought up Danelaw, are there any plans to use that system elsewhere? I really think it's a waste using it in just a single place when there are many places that it can be applied to. Another question to this is is it possible to use between two empires or is it necessary that partitioned titles have a de jure title above them.
No plans but it's in the vast, untamed wilds of my backlog of content ideas.

No reason it couldn't apply to two empires.
I really don't want to be an asshat, but c'mon folks. Compared to other teams at Paradox you aren't the best at communicating/activity/Dev Diaries/sharing stuff to say it the least. At least say/show/tease what you're working on.
Wokeg just wrote a billion paragraph essay on warfare in another thread. They could be better, I suppose, but they do communicate.
I worry about a requirement for weekly dev diaries leading to fluff diaries. I'd rather have nothing than fluff. If they don't have anything ready to show off, they shouldn't post anything, as disappointing as it is not to get updates.
Oh yeah fair point with
@Wokeg he does tremendous job, love reading his comments (even in this very thread).
As for Dev Diaries - let them tease something at least. Maybe write something "hey guys, we are doing progress, but it isn't good enough to show you. But here is something in the meanwhile <X> Dev will tell you about <Y> that he has been researching/is passionate about". Hell, even Tofu (pet) posts. Or maybe just a feedback threads about specific stuff that Devs want to rework in future - just for ideas.
First: ^^ thankee for the kind words!
Otherwise, yeah, I quickly reread the post of mine Flockingbird linked and I think I'd stand by it. As far as I know, our policy remains that we'll post dev diaries when we have a DLC coming up or something else interesting to say (like the yearly reviews). Fillers/teasers/non-development stuff has just caused headaches, so they're likely to be sparsely posted if at all. I wish they didn't, but they do, and the light grumbling of infrequent-yet-meaty DDs
easily beats the flame wars and conspiratorialising that have resulted from segmented or filler DDs.
At the end of the day, if writing certain DDs isn't helping development and only seems to aggravate parts of the fanbase, then the simplest solution is to just not write those DDs.

Apologies that I can't give you a more optimistic answer.
Edit:
speedy reminder that I don't control the DD schedule/policy here, so please take my opinions with a grain of salt.
In other words, they don't like being abused by the "fan" base and keep their cards closer to their chest. No surprises there. Regardless of the quality of the product, being abusive towards the people making it, especially when the "it" is a video game, is a modern day tragedy in gaming culture.
For what it's worth: it's little moments of compassion like this that make the bad days anything like bearable, and this thread has been full of them. It's really, truly appreciated.
CK3 is my biggest disappointment from Paradox (Saying a lot from current standpoint of VIC3). Nothing but let downs since it was released. Bland content, Devs can't get us a pity dev diary with something this massive team claims to be working on.
I'm sorry to hear you've not enjoyed what's been made so far.

I hope we'll get back some measure of trust next release, but I do appreciate that it's been a frustrating couple of years for many.
Wow! I didnt even know about most of these features! You know. If you guys need more Dev diaries, some retrospectives like this from your teams could be interesting. Even help shine light on smaller things Players dont normally pick up.
Aww, thank you. Honestly, I think these days we try to focus a bit more on stuff that's more visible to the player: attention to detail is great but if it comes at significant cost for a reward most won't notice, it's just not giving people good value.
Not to say that we don't try to be accurate or work with historical detail, but it's gotta be tempered by how much time you spend on it.
... which I say
politely ignoring the vizier extravagance modifier script from late last year. Made in collaboration with a very diligent researcher and we uhhh, got
slightly carried away with it.
Hah I knew it! We're getting playable landless characters
Ooph, landless? That would be a
lot of technical work for even the basics, honestly.
I'd like that but teasers don't go over well with the CK3 audience. Eladrin can get away with posting Tofu pictures to pad a three-paragraph DD, but
the last time CK3 teased something the reaction was not the same. The same is true even for
research projects.
... s2g, some day there
will be Agrarian Research Techniques Part 2. I don't know what for, but sheer spite compels me to do it again for
something.
That being said with different reactions it's kinda chicken and an egg problem - with people being negative because of the long periods of no communication earlier.
The tragic thing is, I think you're utterly correct.
This wasn't an issue pre-release/immediately after release. We knackered our early communication strategy hard and now we've gotten ourselves stuck in a toxic loop that sucks for everyone, where the best solution so far has been to just abstain for long periods of time. It is what it is, I guess.
Maybe we'll break it some day, but I don't see that happening any time soon.
Basically, the forum is "full of" (not actually full of, they're just noisy) people who will never be satisfied with a DD unless it says "we are implementing (the feature that user wants) (exactly the way that user wants it).
Very much this, though with the qualifier that things've been getting a lot better on that front for the last year or so for a whole host of factors.
iirc, that dev diary was during a period of prolonged radio silence where everyone was frustrated on trying to find out where the game direction was heading.
Yeah pdx was radio silent and didn't give us any hints on what they were working on. The DD was cool but felt frustrating and lacked any real substance.
This is true, it did come after a prolonged period of little communication from us — the last big thing we'd said (IIRC) was that we wouldn't be saying much until we had something important to say.
There's an argument to be made that maybe we should've stuck more rigorously to that, not launched a teaser two weeks before an announcement, but then... we get a lot of requests to post more teasers, more WIP stuff, more just discussion of what we're working on, so we figured we'd chance it somewhere safe after we'd
fairly recently telegraphed that a DD would mean more DDs and something imminently announcing.
It didn't go well, c'est la vie, but if a teaser bombs because it didn't come ahead of a larger announcement then the key learning there is that that type of teaser isn't really worth while, let alone something that has nothing on the heels for months yet.
Honestly, folks these days seem like they're having a lot more fun with the cryptic hints that Community puts out than anything dreamt up by Design. Which, tbh, makes sense: we're awkward nerds who generally don't do great at public speaking, they're awkward nerds who do.
Orrrrr people are not satisfied by fluff filler while the game is still lacking in the mechanical department
Case in point: we have people in this thread who've said they'd prefer to have filler DDs, we've had people who've said they'd not mind WIP DDs, and (if I may assume a little here) here we've got someone saying that really all they want is something talking about solid mechanical improvements.
All valid views, all valid wants, and I'm by no means suggesting that any of y'all posting atm are being anything less than lovely. Just, we extrapolate this out to a larger community, you add a few bad apples that spoil the discussion or hyberbolise thinks out of context for Reddit, and you see how we end up in a scenario where the only winning move is not to play.