Eligibility of Malaysian Primary School Enrolment?

I would like to know about the eligibility or enroll criteria to Malaysian Primary School.

I was originally Malaysian but converted into Singaporean recently and my husband is a Malaysian with Singapore PR. We are welcoming our first baby soon but considering about the citizenship of the baby: either remain as Malaysian, or become a Singaporean or apply Singapore PR.

If remain as a Malaysian, he can enroll to any local primary school. The Singapore PR status will not affecting the enrollment. But if he is a Singaporean, can he still able to enroll to the local primary school? His father is still a Malaysian.

What is the pro and cons of becoming Singaporean for the child other than the National Service part?

Need some advice. Thanks a lot.