I don't think that is a good enough reason not to do it.
Besides your holdings on steemit and hive grow daily with the inflation of holdings so you're going to be marking income (reinvested income) versus a dollar price for every day of the year anyway and it's not the same amount each day which if you're tracking you're going to have to dump this information from the Blockchains to excel and compare to a price for that day anyway. What real difference will adding curation and author rewards to that export make? I don't think it would be significantly more work but that is my opinion.
Easily reconciled if you take the difference in your "redeemed" rewards from phase to phase, and factor in the median price over the days between the claiming of rewards, when you do it.
Still tough to do, but doable. Gets even more complicated when exchanging or converting HBD for HIVE on the internal market.