If TP receives nondividend distributions, publication 550 says,
If you buy stock in corporation in different lots at different times, and you cannot definitely identify the shares subject to the nondividend distribution, reduce the basis of your earliest purchases first.
If TP keeps track of the lots individually, does this count as identifying the shares? In this case, is it acceptable to divide the "1099-DIV box 3" amount among the lots proportionally?