It has the usual rules on input of all UPPER or all lower case, but is stored internally and displayed as all lower case.
Once I complete the new 'balance' payout code, total unpaid dust payouts will be happening soon after, and current miners will be first off the rank.
Current miners will get it as part of their first block payout after the 'balance' payout code is ready.
FYI, as most probably know, dust does also include the blocks anyone wasn't paid, due to ignoring putting a payout address on their account, before the block was found.