I don't understand what advantage you would gain from withdrawing instead of waiting and risking it being rejected (apart from the loss of fees - which seems the least of concerns if the whole process can take a year, and you seem to be ready to take several months off anyway). But that's up to you.
The 'wait until SA' theory is just that, a theory - it may be true but no real way to know. The logic is that IRCC may check if you have departed at several 'points' along the way, such as at AOR or SA, when ready to make preliminary or final decisions, or at some other specific points in the process (as opposed to monitoring throughout or some other timeline to check). And if you try to only be away when not close to those decision points.
Again, no way to know - it's a logical enough theory and appealing - so maybe it does work that way. But maybe it doesn't.
So leaving aside that the way to beat it is by not being out of Canada for several months ... it's up to you to decide. Best is to avoid being out of Canada for anything but short periods. If you think timing it will help - up to you; it might or it might not.