duplicate account is useful when you have a known username, thus we allow it, however it is for discussion sake, to allow you to express your opinion freely.
not for creating many accounts and joining a bounty > and hence preventing legit users from joining this same bounty.
thus if you want a duplicate account , no problem create it, but let me know to tag it as such
If bounties and airdrops have no problem with a duplicate tag, then you should have no issues joining them