Hi everyone, I read through all the posts and have a sense of what others' experiences have been, and am hoping someone would provide some additional guidance on if anyone else has been able to do the following:

1) My partner still holds MY passport and IC card, but obtained NZ citizenship and passport last year. He was in NZ as PR before that date.

2) We relocated to Australia to work last year, on his NZ passport.

3) His MY passport expires in a few months, and he's hoping to try to successfully renew it, but is aware of the pitfalls.

4) If he flies MEL-SIN, using NZ passport on exit from AUS and MY passport on entry to SIN, is there any chance SIN immigration will let him in with less than 6 months validity, if he explains he needs to go home to renew?

5) Use the MY passport then from SG - MY on the causeway bridge. I take it this is where the system may flag that he somehow magically appeared in SG without swiping out of NZ?

6) Renew MY passport then use it to go back into SG.

7) Depart SG with MY passport and use the NZ passport on arrival into AUS

Would this not leave him in immigration limbo, meaning that as far as MY is concerned, he's hanging out indefinitely somewhere, or obviously using a second passport to enter another country?

Basically the more I look at it, the more likely it seems he will be caught and forced to renounce at some point.