The answer you're looking for is 3 months post expiry of the class 1. Post this, a whole new initial will need to be done.
Where is your reference?
My understanding is that the INITIAL is just that, you can only do an INITIAL once by definition. A little bit like losing your virginity. After that it is via the standard renewal cycle.
https://www.casa.gov.au/information-...iners-handbook