A low technical risk option to reduce survivor grind.
Remove Perk Tiers and have survivors share item/addon inventory.
I -assume- this would be easy to implement.
The database that tracks values for survivor Items/Addons and the perk DB could be edited (assuming your DB has strong command editing language like SQL.)
Making each separate survivor's Item/Addon DB the same DB should be simple enough. You might even save memory as you will only need 1 DB.
You could even just have all the current DBs appended to the same new array.
Comments
I’ve said it before, DBD Mobile did it right in this regard. Shared inventories that is.