I'm gonna put it this way. Don't be silly.
Having a shared address does not imply that that are living in a common law relationship and no-one specially CIC will care.
When you declare a CL relationship, it's because you want to obtain the same benefits or have the same options as a married couple and that is why you have to prove it.
If you're not even looking to get any of this benefits, such as sponsor someone or have them as dependants in your application, it's completely absurd to even think that you need to do so.
Do you think IRCC will go through your address history and then check in their databases for every single person who has lived there to see if the times overlap? That's non sense. Nobody has time for that.