I am NOT an expert and I am NOT qualified, especially NOT qualified, to offer personal advice (with some exceptions which are rather obvious, such as be HONEST, read and follow instructions, and otherwise reiterating well-known answers to FAQs). I cannot reliably assess a particular individual's case let alone reliably state what a particular individual should do.
Generally, you know the drill: if you are in breach of the PR Residency Obligation there is a risk you will be issued an Inadmissibility Report upon arrival at a PoE. The way to avoid that risk is to return to Canada in time to not breach the Residency Obligation.
BEFORE addressing what can help further, to be clear, at the risk of being overbearing and redundant, once a PR is in breach of the RO there is a real risk of losing PR status. If that risk can be avoided, that is the far better approach no matter how many positive H&C factors the PR has. Far better approach by a lot. And second to that, otherwise, if and when it is impossible to avoid a breach of the RO, the next most important thing to do is get to Canada SOONER rather than LATER.
That said, many forum participants appear to grossly underestimate or even exclude the value of all sorts of factors . . . but there is a backstory to that, and that backstory is written in tales of woe told by scores of former PRs who lost PR status notwithstanding all sorts of reasons why they failed to come to Canada sooner. With only narrow exceptions, H&C cases are almost always TRICKY and most often DIFFICULT, which to be clear means there are few if any easy-pass factors.
". . . would you rather recommend renouncing my PR and add myself to my spouse application once she receives her PPR?"
No. And I say this even though, again, I am NOT qualified to offer personal advice, and I try to steer away from making recommendations.
BUT this is an easy call. As long as you are still within the first five years since the date of your landing, and especially if you can make the physical move to settle in Canada within, say, 42 or so months of when you landed (the 3.5 year frame you've referenced), the chances of NOT being reported at the PoE are good enough to make that the preferred approach. And even if you are reported, and issued a Departure Order at the border, you can still enter Canada, appeal the Report, and stay as a PR in the meantime (including legally work and so on) . . . and if as a family you are staying, yes that should make your H&C case stronger for the IAD when it decides the appeal. Strong enough to place your bet on that, but also knowing that even if you lose the appeal, yes you could then be sponsored for a new PR by your spouse and probably get an open work permit pending that process (with a gap in time . . . but if and when it comes to that, well over a year from now at the soonest, you can reevaluate your situation and go from there, and I'd guess you will be able to figure out how to best navigate through that, IF it comes to that).
Moreover, it is simply better to remain a PR while your spouse proceeds with the PR visa process. Even if you are reported.
Remember, if you renounce your PR that will render you a Foreign National. If you are then added to your spouse's application, which you will NEED TO BE if that happens any day prior to the moment she is actually granted PR status (that is, when she actually lands, not just when she is issued a PR visa), THEN YOU will need to go through the whole examination process yourself, again. That would likely
DELAY the issuance of your spouse's PR visa (assuming your spouse is indeed on track to get a PR visa, which again you appear to be overly confident about), while you undergo the background check, medical check, and so on.
[ As to the importance of adding you to the application if you renounce or lose PR status before your spouse does the LANDING . . . . be aware, notwithstanding the implementation of a recent pilot program somewhat mitigating the draconian impact (a forever ban on sponsoring the omitted spouse) of a failure to include a spouse, and have the spouse examined, UNLESS you do in fact have PR status right up to your spouse's landing, you absolutely will need to be declared and EXAMINED . . . even if your spouse has already received the PR visa. Your situation may pose some complicating factors, given your spouse has already referenced you as a spouse in the PR visa application (but without need for examination given your PR status); but there is little doubt, your spouse's immigration via a non-family class application (such as FSW) will proceed more smoothly if you remain a PR, whereas if you, in the meantime, become a Foreign National that will, AT BEST, complicate things . . . and remember, a bureaucracy is what a bureaucracy does, and a bureaucracy tends to NOT do complicated well.
]
More Regarding Positive Factors Which Reduce the Risk of Losing PR Status --
You do not mention whether or not you have traveled to Canada during the last 33 months or so. The more you have come to Canada, the less time it has been since the last time you were in Canada, the better your odds of being waived into Canada without being examined for RO compliance, let alone actually being issued the 44(1) Inadmissibility Report. Even a short trip BEFORE you are in breach of the RO could help, especially if the purpose of that trip is explicitly attendant preparation for your return to Canada.
My sense is that the cost of health care attendant a pregnancy and birth may very well be a significant factor favouring relief from a strict enforcement of the RO . . . but there are also elements of this pushing the other way, ranging from the personal decision aspect to the period of time prior to the pregnancy during which you could have returned to Canada. Indeed, this one factor illustrates how complex and multifaceted even a single factor can be, making it very difficult to forecast a Canadian official's decision-making, even as to whether the factor is considered a positive or a negative factor, let alone how much weight it will have in the decision-making.
As long as you are prepared to fully explain all the reasons why it has taken you this long to come back and settle in Canada, truthfully of course, and you do in fact arrive with well over a full year left before the fifth year anniversary of the date you landed:
-- you should have a decent chance of being waived into Canada without being examined about RO compliance, and
-- even if examined, a good chance of being waived into Canada without being issued a 44(1) Report, and
-- even if issued a 44(1) Report a fair chance the Minister's Delegate will make a favourable H&C decision and not issue a Departure Order, and
-- even if issued a 44(1) Report AND a Departure Order, you can still come into Canada and appeal, and if you STAY pending the appeal, and your family settles into Canada in the meantime, a decent or even good chance the IAD will decide to let you keep PR status despite the breach, AND
-- even if you lose the appeal, and thus lose PR status, your spouse should then be able to sponsor you for PR again
I have deliberately used terms like "fair chance," "decent chance," and "good chance," to reference varying probabilities. These are as best they might be quantified.
The fact that you have a PR spouse who can sponsor you if you lose PR status is indeed a factor which will likely be considered by any of the officials, at any of the steps referenced. However, it alone will NOT make the difference. In a close case, and especially if IRCC perceives the individual is actually NOW settled permanently in Canada, it can tip the scales toward allowing the PR to keep status. But many PRs in this situation have lost the appeal and actually part of the explanation for why their H&C case fell short has included the absence of hardship SINCE they could in fact be sponsored to be a PR again, if it really is their intention to settle and live in Canada . . . but most of these involve PRs still spending a lot of time abroad (typically about employment abroad), and the idea is that IF and WHEN they are ready to settle in Canada permanently, then they should be sponsored.
Overall, family in Canada, plus stay in Canada pending an appeal, and a breach on the short side (the shorter the better . . . with longer than a year elevating the hurdle considerably), together with a fairly good explanation of reasons for not coming sooner (even if those reasons do not excuse the failure to come sooner, but are at least a reasonable, rational explanation), should make for a fairly good H&C case on appeal.
That said, back to overbearing redundancy: the best possible H&C case is NO WHERE NEAR as good as simply getting back to Canada in time to avoid a breach of the RO.