A little message because I faced a problem many times in the game, so I will talk about my last sad experience :
I paid 50 gems to remove a 3rd perk of an item, and had the XP bonus, but I didn’t want it so I waited the time needed and paid again 50 gems to change it. And then… XP bonus again… moreover it was less interesting than the previous one ! I knew I will have maybe several attempts to succeed to have the 3rd perk I was expecting, but having the same twice (and that’s not the first time I face it with the XP bonus) is REALLY frustrating when you have paid 50 gems for it.
So ! What I suggest :
Have a system that doesn’t offer you twice the same bonus
Have a system to go back to the previous perk if we are not satisfied without getting back the gems we paid and this choice will be permanent. Maybe it will be good to have a save of the previous perk (instead of delete it, it will be like transparent and inactive ?) and then when a new perk appear we can choose to have back the previous one or pick the new one ?
Thank you for your attention !