I am confused by the stopover rules with air canada.

I am looking at a flight from somewhere in Europe (probably DUB) to HNL. I would like to have a stopover in YVR. Ticket in J (booking class P).

now, if the layover time is less than 6 hours, does this mean you can never have a stopover?

and if the layover time is more than 6 hours, it says you even get a free hotel if you want to make a stopover (for 'business class', no mention of difference between low and high), whereas stopover rules for class P are 'not permitted'

and finally, if you have a layover of more than 6 hours in YYZ and less than 6 hours in YVR, does this mean you can do the stopover only in YYZ, or also (or better: only) in YVR? Again, nothing in the rules about this, it seems