> The re-shuffling of the coins is for the exchanges security and accounting
Neither requires re-shuffling. It's just for convenience and what be even more convenient if every blockchain tx included who they are trying to deposit to providing inputdata even for regular transfers. Like a tag, "these 10 eth for personal_Hash=abc123"
Actually that would put the onus on the sender to include extra pieces of data, and the exchanges would have to deal with errors from people who send without the hash.
So I'm pretty certain even if it were supported, individual addresses would still be the better choice due to ease of use.
Neither requires re-shuffling. It's just for convenience and what be even more convenient if every blockchain tx included who they are trying to deposit to providing inputdata even for regular transfers. Like a tag, "these 10 eth for personal_Hash=abc123"