Last week at YYC we boarded at a B gate. There was definitely more room here than many of the C gates. I arrived a few minutes before boarding, and while a few people were hovering around in the far back, no one had gone into line. There were separate Z1 & Z2 lines plus the usual 3-6. After observing for a couple of minutes (gate checking bags and a pre-boarding), I went to the Z1 signpost to wait. Boarding commenced on-time, and it took 35+ minutes to complete the boarding of the 321. The last 5 minutes or so consisted of pax making their way back to the front to either gate check their bags or try to find space (with the help of the FA's) in the J cabin. I have no issue wiht any pax using free J space on a domestic flight (with FA assistance/direction), but I did notice the FA remove a J pax computer bag requesting it be stored under their seat to make additional space. I'm not certain about this one....