Milestones aren't dates and they don't happen on a schedule. Milestones are
EVENTS that might be DUE to happen on a certain schedule but that's a
different thing altogether. Milestones happen on whatever dates their
predecessor tasks drive them to happen - that might be before, on, or after
their respective due dates. The project schedule ought to be predicting the
dates they're going to happen, not document the dates you need them to
happen. If the predicted dates don't meet the required dates, then you have
to change the driving forces within the plan. Using a recurring task to
place them on specific dates or at specific intervals doesn't do that, it
merely documents your requirements but does nothing to help you actually
develop a plan that will achieve them.