Make it’s I you can burn 25 legendaries or so to reroll a dead perk on a legendary unless it’s a named one with preset perks you could even add an azoth cost. Here’s how it’d would work
Salvaging a legendary item if you have 600 expertise in that item you give a stackable item which you could then use 25 of those in a unique station (fill in the blank name) to re roll a perk.
You could even make it so the amount you put in influences the quality and quantity of the perk pool.