I was having dinner with some former Singaporeans last night in Perth. The older of them had been in Oz for nearly 15 years now. He related 2 anecdotes which I found quite enlightening.
The 1st story was about his son. They had migrated when his son was 7 years old. In those days, you only needed 2 years as a PR before being eligible to apply for citizenship. So the parents got their citizenship pretty quickly and managed to get their CPF out after renouncing their citizenship. When the son turned 11, they applied to CMPB to get him deferred from NS. They were told that they had to 1) register him for NS and then 2) apply for deferment. When they asked if this would get him out of NS, there was no clear answer from CMPB - just a "case by case" answer based on what "benifits" his son had received from Singapore. Anyway, faced between a choice of not registering the son at all and making him a fugitive, OR, registering him and then applying for deferment, and hoping this will be granted, they took the latter choice. Fortunately, he was granted deferment, but his point was the lack of clear answers at the point of registration that made people unnecessarily anxious. They found out through other means that "benifits" meant getting their son's NRIC, and renewing their son's passport. Fortunately, they had done neither - so the son had NOT received the "benifits" that would tie him down to NS.
Anyway, they completed the next two steps as well, applying exit permit at 13, and again at 16. And, just a few weeks ago, the son turned 21 and he submitted his renunciation of citizenship. It seemed that ICA requires 3 months for the approval for the renunciation, and now they are waiting for the final letter to wash hands off Singapore.
The story above seems to gel exactly with what Scroobal had mentioned previously - so I am happy to get a confirmation from a 1st hand person who experienced the excruciating process. I guess these are the steps to follow in, when the time comes for my own son's NS process.
The 2nd story is about himself . He had already given up Singapore citizenship many many years back, and was on an Australian passport. Then a few years ago, he company wanted to send him to look after their branch in Singapore. So now he would be an expat. But when they applied for his employment pass, it seemed that the Singapore government was tracking his "ex-Singaporeaness" and gave another stack of forms to fill out - which asked for his parents personal details (now deceased) like what the father worked as, etc, his siblings details - including NRIC, address, etc. He was pissed off and returned the unfilled application back with a letter saying:
"I am not applying for a job. I already have a job. I am not applying for permanent residency. We have a choice of setting up our company in Singapore, Hong Kong or Shanghai, and we chose Singapore for business reasons. If you have any issue about granting me an employment pass, please let me know, and we shall shut down our branch in Singapore and we shall pull out our operations and move to either Hong Kong or Shanghai as required." He copied the letter to the head of another stat board.
He received a reply shortly, stating they apologised for the incovenience, and he would be issued his employment pass without any further delay.
Of course, I have no corroboration as to whether the second story is true, but there seemed to be no reason for him to make up the story. If true, it shows that the SG govt does track those (or at least some) who give up their citizenship, and then make it very hard for them to get back into the country.