It’s a little on the annoying side to lose time from the Eden Merit XP/Drop rate buffs unless you happen to be using them in a dungeon you have the warp to booked. How about instead of it being the direct effect the trade in results in a character bound version of the respective item?
PRO: Can use at your leisure as opposed to having to make a mad dash to maximize effect.
CON: I guess someone with Merits to burn could get enough to turn into boxes to sell?