Finn Welder can be found in Silverton, inside Locks & Keys.
He specializes in module exchange, allowing you to upgrade modules by trading lower-tier ones.
— 3 modules of the same tier can be exchanged for 1 module of the next tier.
— The exchange requires Gold nuggets.
After receiving a new module, you can reroll the result up to 5 times to try getting a different module.
⚠️ Each reroll costs Gold nuggets, and every next reroll becomes more expensive than the previous one.