RedShoedRider- I think it's up to you. You're used to them and know how slippery or not slippery they are. Based on that, try to gauge how well you'd be able to prevent a fall if your stoker did something you weren't expecting just as you were preparing to stop. Or, if your stoker is very good at staying still until you are stopped and give her the okay to move, then maybe you'd be fine.
Only thing to keep in mind is that, on a tandem, there are times of confusion. There would eventually be a time that you have to get a foot down quickly and at an unusual position to keep the bike up. Especially in group rides or while trying to follow cue sheets on unfamiliar roads.