I do wish they would make them reprogrammable for future visits. That would be a much greener solution, and they could offer a discount for future visits.
Indeed. The technology allows for such things. If you can add a day during your current stay, then you could add a day in 6 months, or in 6 years. It would work the same way.
A time limit between refills is a non-starter for me. Unlimited refills is unlimited refills. Not refills, within certain time limits. Limitations on the number of refills, during a meal, for those not buying a mug is also bizarre. I don't know of any restaurants in America that don't do unlimited refills of soda fountain drinks, especially when it is self-serve.