As a few threads have stated, the treasure vault is kind of a let down.
Very few crowns
A lot of crystals; the majority of which is left behind
Uninteresting gameplay (unless you like breaking crystals and lawnmowing bushes?)

I really enjoyed the treasure room in LoA. Yeah it was a lot of clicking and breaking boxes but players could see that they were getting rewarded.
So, why not make the treasure vaults similar to the reward room in LoA?

The vault room could be laid out so that there are two options;
Get a few cr, heat or vials from a few boxes and go to the elevator or
step on a party button and continue forward. (like in the arenas)

If the party chooses to move onwards, they would have to travel through a whole series of traps (protection against thieves).
Traps could vary from spikes,vents, wheels, drones, etc and maybe a few trojans..they seem to play the guardian role in sk ._.
The traps wouldnt be simply laid down..it could be a puzzle where knights have to figure their way towards the treasure.

At the end, knights are rewarded with multiple treasure boxes, like loa, but of course a reduced amount.

As for aesthetics...well the current treasure vault doesn't feel "vaultlike", its not enclosed or anything,
It feels more like a resting ground and i understand that the description for the current vault says that its a place to rest your feet
but...its a treasure vault :<..

tldr
Change the vault into a protected treasure vault with more loot :B..