I enjoyed the Zeal of Zenithar even this year, but encountered a few pain points, and also have some thoughts for improvement.

The Crafting Research scrolls offered in the boxes cannot be Fenced or Laundered, so if you got the scroll in a box that was stolen on a character with no use for it, your only option is to destroy it.

Maps need to stack. Having to stop playing with my friends to go and use maps because they are making inventory and event box management a PITA isn't a particularly fun mechanic.

Keys need to be Account Bound. While I tried to keep the focus on my main character, I inevitably wound up with boxes, and by extension, keys on alts I don't necessarily need or want them on.

Companion gear overload. I appreciate the thought here, but I got around 200+ companion gear items, and only two were the slot/trait/quality I needed to either want the item for use, or to use it to upgrade the quality of the item my companions were already wearing. Companion gear needs to be a less winning the lotto type of system in the game. When you clog my inventory with gear I don't want, can process for mats, can't upgrade, can't use to learn the traits on, it just feels like a waste and aggravating. ESO has a great crafting system for gear already, I am amazed ZOS decided to ignore it for drops that are almost impossible to get the one you want.

Considering the crafting focus of the introductory quest, and of the festival grounds setting in Belkarth, I was disappointed that the rewards focus was so heavy toward Provisioning while very minimally dropping plans for the other crafting skills, and the furnishing mats needed to make them. Hopefully next year most crafting patterns that drop in the world can be added as rewards in the boxes, as well as mats like mundane runes, heartwood, regulus, bast, etc.