I am a current Koodo customer in good standing. I just added another line (for my 17 year-old) and Koodo did a credit check in which my credit took a hit! Why would you need to do another damaging credit check??
Plus it's a "soft" credit check, which does not affect your beacon/credit score. If you were approved it is actually a good thing, if you start applying for credit "everywhere" and get denied that is when it starts to negatively affect your credit score