If you run cron/senddigests daily, periodic digests will be sent daily including the first of the week and the first of the month> If you run cron/senddigests weekly only, periodic digests will be sent weekly and> if you run cron/senddigests monthly only, periodic digests will be sent monthly.
Sorry if I'm being thick headed with this. I think I understand. Just to be clear ...
With the default Mailman cron being set as noon daily:
If, on a Wednesday (for example), List-1 is set with its digest as Daily -- its digest will be sent at noon that day (and every day).
And if List-2's digest is set as Weekly, its digest will be held and not sent until noon the next Monday (the first day of the week). The Daily digest of the List-1 will also get sent that Monday.
Have I understood correctly?