Friends,
I just completed landing with my family from New York to Toronto through the Peace Bridge. I want to inform everyone that the time restriction (8am-midnight on Tue, Wed, and Thur) is only for people who are flagpoling. I was not flagpoling. I live in New York and I was able to complete my landing via Peace Bridge and apply for PR card as well on a Friday evening (Friday, 29th March 2019 at 8:00pm).
The immigration officer inside the building asked me if I live in Canada. I said "No", and told him that I live in New York and I am performing my landing. Then he proceeded to process my application. I did notice that they had different file baskets labeled "Flagpole" and "Regular".
Please note that calling the CBSA would not clarify the weekend landing confusion. I called CBSA peace bridge before driving to Peace Bridge and I was told that they don't have people to process PR applications on weekends. However, I still wanted to give it a shot, so we drove to Peace Bridge and got everything done without any issues. This means that the people that answer the phone from CBSA are not fully clear on this.
Hope this helps.