Then no problem, totaly remove brown boxes from cash shop and let them be in event.
Let cashers and non cashers struggle for good stats on gear.
If you disagree with this one, that means that you as cash player want to dominate game and prevent all other players from getting stats.
Silver boxes should be in world boss event since with them you select stats you want to get and they should be hard to obtain for casher or non casher via events only.
I agree with this, brown boxes only benefit those who spend money in the cash shop, get maximum statistics, upgrade their equipment and already (sorry not english)