"Of course, we prepare estimated payment vouchers for lots of clients who don’t use them."

So you would save time for those that do use them and eat up time deleting them for those that didn't pay the estimates.  Or eat up even more time dealing with IRS notices because we forgot to check to see if they were actually paid and the return went out the door showing estimates that were never paid.

It only takes me a few seconds to load in estimates paid so in the long run, the current system seems to be more of a time saver.