I only messed with it minimally as I wanted to just get my Heidel storage unstuffed and get those workers back to work and make a pve preset to finish the weekly I started yesterday, but:

Kydict's Adventure and Giant crystals seem to be considered the same type for the purpose of being limited to 2.

They have different bonueses and used to be Helmet (Advenure) and Armor (Giant) so you could use 2 of each the old way.

Now you are limited to 1 of each or 2 of either, instead of all 4.

No limit to Kydict's Crystal - Adventure.  I'm using four in one preset.

Like I said I had only played with it a bit initially and logged out since, but after putting 2 Adventure into the preset, the Giant's were greyed out / unable to be slotted.  So it seems to affect the Giant ones, but not the Adventure.

After looking through the crystals and groups, my bet is that PA will fix things and then reset crystal placements, so that we'll need to redo this again soon.  There's some odd things one can do with crystals right now that may not have been intended.

So the issue is the Improved Resistance II category.  There are piles of crystals in this group that were used in Helmet, Gloves, Armor and Boots.

This means that you previously could use 8 of the crystals in that grouping, and are now limited to 2.

Sounds like a large nerf to variety and convenience, if not just a very obvious oversight.