Two ideas, somewhat related.
The first is based on how to solve the confusion people have around what is purchasable during an event (for frags or not). The second is to solve the confusion caused by items being purchasable for frags, as well as claimable for souls.
1. Can we have an "Events" tab in the store?
If you can't purchase anything for an Event, it's blank and says "No event items for purchase at this time".
If there's an event, you put ALL the event items available for purchase in here.
eg: Night City event stuff would all be in here. All the Shadow Souls/Wickerman/Ferryman event stuff would be in here, etc.
The standard tabs are way to cluttered.
2. When fragments can purchase stuff int he store, stop them being redeemed in the Fragments area, and point them to store.
Basically, during an event instead of allowing the fragments to be converted into souls in the fragments area, replace the "Claim" button with "Go to Store" that would take you straight to the Events tab suggested above.
Additionally, add a store item for the soul at the cost it would have been converted in fragments. eg: Wickerman Soul for 400 Wickerman fragments.
At the end of the event, the "Go to Store" button gets replaced with the usual "Claim" so they can be turned back into souls.
Note: The "Convert" button stays as is always - so you can always convert them to Precious fragments.