Okay, having researched the above problem as much as I can, it seems the only mention of visa stamps I can find across the whole official CIC guidelines (aside from the BOWP application) is that it used to be a requirement on the old version of the checklist (I found an old one from 2009 on a lawyer's site).
Since that line has now disappeared from the current checklist, I'm hoping this means it's now not an absolute requirement especially so since it mentioned visas, and in my case I'm visa-exempt) I can breathe easier.
Here's hoping the AOR comes through soon (for everyone!) and I can stop obsessing about little things like this!