I thought of that when I read your post BUT the problem I see is that when the case of all coins are divided as would happen when paying farming that way, then there is only enough divisions that can fit in a MB of data. Paying farming would exceed that so quickly its not funny.
Also you need a coin in order to divide it. Who owns the coin?
I still feel that another MD tag type is needed for divided coin which holds the amount of divided coin in the particular wallet. (yes the wallet address is the balance holding MD address too) When a coin is divided it is frozen by the network. About Easter this year I suggested that system and still seems the best way so far.