Add learning plan date setting to align with workshop/unit dates so due dates can be applied properly

It would be beneficial to include a date setting on learning plans where the due date or access end date can sync with the unit end date of the linked enrolment.

For example, we ask students to do an online assessment for first aid prior to attending face to face practical days.

There is no LP date setting available so we can set up the modules and included assessments to have a due date automatically applied which is relevant to the workshop/unit dates. I can't set it as [2 days after commencement date] or anything like that because the student commencing date will never be consistent across any cohort.

Assessment Plan scheduling had the option to match assessment dates to unit dates and this worked really well for this purpose but this is missing from Learning Plans and needs to be added for greater control.