Ah yes, Once I completed my 1,000+ days in Canada, the thought of applying separately for citizenship didn’t even cross my mind. It felt natural to submit our applications together, just as we had done for permanent residency. That process had gone smoothly, so we assumed the same would apply to citizenship. In retrospect, applying as a family may not have been the best decision.
To be fair, we might well have made the same decision over here. (This despite having a slightly less smooth experience with PR than you seem to have had.) The main reason we didn't is because my wife decided not to pursue citizenship at all.
One couldn’t apply for Canadian citizenship without first meeting the residency obligation (RO) required for permanent residency. However, once a person has applied for citizenship and later needs to move out of Canada for any reason, their permanent resident (PR) status remains unaffected—regardless of how long the citizenship process takes. Correct me if I am wrong.
You are wrong. One must remain in compliance with the residency obligation until one becomes a citizen.
This is a corner case admittedly - one has to either/and be out of Canada for quite a while and have one's application take a very long time indeed.
In fact, recently we had one person report having a citizenship app stuck for almost four years, see
https://www.canadavisa.com/canada-i...-for-citizenship.333455/page-74#post-11087172
(Though it seems this is related to coming in as a refugee originally, thus, definitely a corner case and not applicable to OP's situation.)
I'd agree that in most cases, the citizenship is approved and gets to oath before enough days are lost for the RO to be put at risk. And this could be worse - it's just the RO that has to be maintained.
So even for those long citizenship cases, one could imagine leaving Canada after having 1095 days of physical presence in the last three years, and then returning after another three years (i.e. returning just in time to prevent RO from going under the minimum 730 days). If it was the stricter citizenship physical presence requirement that had to be met (that is, keeping 1095 of presence post application), one wouldn't be able to leave for as long.
Likewise, if it's a PR married to a Canadian citizen who is in turn applied for citizenship for themselves as well, then the PR can follow the citizen abroad and maintain RO by staying with the citizen, despite being out of Canada. Under the citizenship physical presence rule, those stays spent with the citizen wouldn't count since they're abroad, but those days DO count for RO. So PR would be maintained even for cases where the citizenship app takes extremely long (4+ years) and the PR is abroad (but with the citizen spouse) for the same time period.
Edit: Found another case, that dpenabill mentioned some years ago, where the wait time was twenty years (20) !
https://www.canadavisa.com/canada-i...ant-waiting-for-the-test.668764/#post-8369537