It is done... Thanks to Zollymonsta for being the sacraficial Guinea Pig... I've modified the original emulator instruction thread to reflect the changes needed for Saturn setup, but it's quite simple really.

Note that just because there's a lineup doesn't mean there's guide data for all the channels; the guide data has not changed, so if you didn't have data for a specific Saturn channel before, you won't now either. But you will be able to pull the guide data and channel lineups off the emulator rather than using loadguide and doing the manual thing.

Anyone who's already on the emulator (or for that matter on a manual setup) and using it with Saturn can go, in the Tivo GUI, to msg/setup, restart, re-run guided setup, then follow the emulator instructions for GS and Saturn. Once done, all existing programs, passes, etc should be preserved, and you should be on the new lineup with all your Saturn channels there.