But to the extent measured in the tens of hours? It'll happen, but it probably isn't too much of a stretch to assume that it's going to move at the speed of plot more often than not.
I can't think of any serious application that would take tens of hours. At 1000 words per minute, 99% of the spells actual use* will take a minute, or less. Military reports, troop deployments, maps, contracts, legal papers (such as release papers), and any of dozen of other things I can think of a use for having a copy of will all take about a minute. If the GM rules that by saying 1000 words/minute it produces ~100 words per round - many of these will take a couple of rounds, not tens of hours.
If you want your character to invent Graphic Novels as a medium, that is surely a downtime action. If you want to write a 1000 page memoir of your time as an adventuring wizard, that's a downtime action. But even without magic you'd be doing this stuff away from adventures anyway, so that doesn't change.
*As in stuff that will take place during a real game session
, as opposed to thought exercises taken to the extreme. Does anyone seriously have a GM that makes them go and duplicate the entire Bible as an adventure