It's not to say that it's impossible. But it can put your application at risk is all. If you bring proof of your application for PR, and be prepared to show ties to your country of origin (thus satisfying dual-intent (google that and prepare for it, just in case)). You might also want to bring a copy that you paid the fees already. Also bring proof that you applied for an OWP.
All of these things show the CBSA officer that you are following the process, and you understand that you can't just take up residency.
If it''s a family emergency drawing you back, when you return you could add to your explanation that you had to return to deal with that as well.
A little story about dual intent:
My wife showed up at the Toronto airport with her dog, and bags in hand (not everything, most had already been shipped in smaller boxes before she arrived). The CBSA asked what she planned to do here. She told them, "To be with my husband". This provoked a longer discussion where they entered information into GCMS about her, me, etc. They tried to tell her she cannot just show up to live here. I guess they didn't get that she planned to apply for PR inland. She would be entering as a Temporary Resident, but seeking Permanent Residency. This is the dual intent. She also had no return ticket. Anyway, they let her into the country with just a stamp + a date (6 months from entry). No visitor record, or anything other than some notes into GCMS and the "You can't do that" speech. Which we have already mitigated
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