It’s pretty clear that there isn’t a single, issue-free way of getting a totally flexible, Z1-9 day Travelcard on a Smartcard. Thanks to all for input and experimentation. I just wish that somebody knew how real-life tube challengers actually managed (not planned, not intended, not believed) their ticketing for their challenges. Looks like no joy on that front. I’m wondering now, for my own challenge, if the only way to get a Z1-9 on a Smartcard which will definitely work is to get a weekly one. Costs more, but I wouldn’t want hassle on the way round.