The timing datatype has a required binding for timing.repeat.when - I think this should be loosened to extensible or example. There is a lot of variety that could consitute the definiton of when: "Regular life events the event is tied to". Right the provided valueset is rather small. I recommend loosening the binding and not just adding more values to the valueset as there is too much variability to capture 100% of all possible values in a required binding.

Examples of some life events Epic can capture in relation to when a medication should be given: during travel, for an appointment, for a procedure, before sex, before exercise.