what are the implications of the changes in the aging schedule from one year to the next.

There should not be any complications.
You just maintain the continuity procedure.
The periodic principle is for convenience only,
it should not interfere with your standard
practice.
Make sure that you control tightly all amounts owing.
The best way here is to bridge every month
to the previous one.
This can easily be maintained by a series
of EXCEL spreadsheets.