I am planning to move back to Canada without her if this accelerates the process. But I am not that it does.
No-one can tell you for certain that it will speed things up. It for the msot part depends where it is in the process.
Since you're a Canadian sponsor abroad, though, it's possible it will if it helps resolve any line of questioning they may have about your intent to return. My guess is that on the balance of probability it would likely help but I can't say how quickly it would result in the ppr. You'd have to weigh against other things like how long you have been common law (if eg >2 years or so, probably not an issue). And of course Iv'e no idea how long a separation may be. There's also the possibility that a new TRV application after you returning to Canada and advising IRCC would get approved.
My suggestions would be in order:
1) If you've already received requests for more info about intent to return, then you've already been told the relevant info (returning would likely help).
2) It will cost you very little effort or trouble to provide more info via webform about any of your preparations to return - hope you have some. Submit them via webform and it won't hurt.
3) Order GCMS notes. If there are any notes or text about the intent to return issue, now you know - it is an issue and returning will likely help. (You may find other relevant info there of course, to whic you can also try to be responsive)
3) At that point if no indication (ie. > one year after submitting), well, you'll have to decide if no further info. Truth is 80%+ of apps are going to get PPR within 12-14 months (whatever the number is now), so it may just come while you're going through this.* At that point I'd say worth returning but instead of trying to decide now, prep your return in the interim and see what you think then and whether any new info has come to light.
*Side note that as a result fo this, it will be hard to say that anything you did had any effect. It happens that people think the things they did helped, but it was already going to get done without any additional info. That won't stop most applicants and sponsors from trying, of course.