Writing an update here in case anyone is thinking of flagpoling soon...
I just came back from the Boundary Bay Border Crossing a.k.a. Point Roberts where I officially landed as a PR. I got there purely using public transportation, and it was very convenient indeed - I was back at our South Vancouver apartment a little over 3 hours after I left. It would obviously be even faster driving, but then you'd have to think about parking and traffic.
I got off the bus on the corner of 1st and 56th, and I made the short walk down 56th to the border on foot. If you stay to the left of vehicular traffic entering the US, you should eventually see a footpath to the US border office. There are painted footprints to direct you as well. Once inside, there would be officers there attending to anyone crossing the border, and they are very familiar with flagpolers. If you mention that, they'll know what to do. I showed them my passport with my US VISA, and got it back after a minute or two along with a piece of paper indicating I flagpoled there.
Next step is to head back to the Canadian side. Just go back in the direction you came, except this time turn right before the Canadian border office and go in the direction of vehicles entering Canada. You should again see painted footprints to guide you. An officer will call any "walkers" over and ask what your business is, which in my case is landing as a PR. He will give you a slip of paper and direct you into the office. Once in, when your turn is up, hand over your passport, COPR, that slip of paper from the Canada border officer and the one from the US border officer and they should begin to process your landing. After that, it's a matter of waiting for any other instructions. I actually did not list down any goods to bring in. Since I have been staying here with my wife, I have everything I need here. I brought this up with the officer, and he said I can make a list of goods to follow if there are any, but anything I have here already, I don't have to bother with since it's moot. After a few more questions, answers and signatures, he handed me back my passport and a copy of my COPR, now stamped and signed, gave a few notes and reminders, and that was that. I had brought a few other documents with me (birth/marriage certificate, bank statements, medical records, et al), but they weren't necessary apparently.