Does it really matter? I'd be surprised if they even read the ballots. I imagine they just get shipped over to a big paper shredder while Putin decides how much he's won by this year
Makes it easier for those that do the counts to feign ignorance and they have 'evidence' of ballots for any potential external warchers of the election.
United Russia and current Russian government really love to go through the motions and put up a facade, as then their supporters have additional grounds to retreat to in their demagogy.
They can always say "Oh but look we counted the ballots it adds up!" and if you point at manipulations like these they can say "Oh but these were unique cases! We excluded them and the votes still add up!"