First time really using TTS to play a board game and I absolutly love this mod. Well done!
I do have a couple of feedback from playing the base game, I haven't tried the expansion yet.

Boss minion strength:
The undead king attack card Command Order says the minion strength is based on the red rune. However, the boss board says the minion strength is based on the green rune. Now there is also a skeleton archer minion card to add to the confusion. I couldn't find this card explained anywhere (I may have missed this). The HP for the minion is also confusing. This card says the skeleton minion has 3 HP while the boss board says the minion HP is based on the player number. Perhaps updating the boss board to be the same as the one in the adventure book page 12 would solve the problem.

Boss HP:
The boss HP is also a bit confusing. The boss board says 20X (20HP per player) while the adventure book on page 12 says 30x (30HP per player).
The solution may also be the same as mentioned before. Update the boss board to be the same as the one in the adventure book page 12.

Gameplay beginning of chapter 2 with darkness and threat card:
You'll take damage in this room unless you spent an AC to get extra movement, because there are no monsters. Three steps is inssuficient to reach the door. I feel spending an AC to open the door and walk further is mendatory, because the darkness will spawn and they are very unforgiving in this update.
In this room there is an interaction token that can be reached after three steps. I unlocked a room with 2 treasure chest. Seeing how unforgiving the darkness is and the additional damage from the threat card, reaching those room is not an option.

A suggestion would be to have the threat card and darkness active after opening the first door. Players just came from the camp, so I don't see a reason to force them to move quickly as they are fully recovered already and doesn't need to stall.

Adventurebook shortcut:
The jumping to chapters works in the beginning. Later on it gives an error
Error in global script; attempt to index nil value. I've played twice and it just doesn't work at some point. Unfortunatly I don't know what triggers this error.

Retrieving deleted items:
I accidently deleted heroes mini or familiar tokens. Where can I find them back?

Apart from these little nit picking, love what you've made!