Someone else suggested CK2Plus which I rather liked.
CK2Plus is nice... Short and simple

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I looked at it but I have to say I'm not a fan of throwing in even more personality traits when characters already end up with so many contradictory traits.
I see your point, in the end of the day I know you starting looking into this already, but hopefully you go into greater detail with the negative traits or even positive traits, cause at the moment, the negative traits are exactly what they are mostly, which are "negative", and "positives" are exactly what they are too... I'm hoping we can get a few in-between or even refine the existing traits to make you wonder, "hmm... Perhaps the Negative trait is more useful than a positive for the extra +2 in Martial I'll get, in exchange for -2 Stewardship.." I am aware some negative traits have situations like this, but I think if we can have more of a choice that would be awesome for the RP experience.
There was an excellent general post about it, but I simply can't seem to find it now as posts just move to quickly in the general boards, heh.
I do think we could perhaps use more "positive" genetic traits, as right now the genetic negatives severely outnumber the positives. (I guess was the case historically, but perhaps thinking from a gameplay perspective, as this is a game after all..)
I also know there's been quite a discussion of "Grand Tournaments" on the general boards ironically which is funny as I asked about that before if you could perhaps look into that, as to me that's such a feature event that could be very intriguing to tweak, heh. (but I personally don’t have the patience or desire to do so myself, lol) Finally, I've probably mentioned it before, but one of the things that is almost an afterthought, is the "Reagent" system, I think adding more events and features would bring a whole new dynmaic to under-age rulers, I am aware there’s a concept mod going on about it, but who knows how far that’s gotten.
Ohh and good call on the HRE Revised Mod as that does look interesting which makes me wonder if the whole "Coronation" thing can be something to consider even for newly appointed Kings too.
Well that is all for now , till I perhaps come up with more ideas later, hah.