This information is not available on the trackers. You have to call and ask IRCC about all three stages of BGC. In my experience, I think the information we do get about BGC is probably inaccurate because the call agents don't have all the info.
Update: Received P1 today @ 9:22 pst.
I replied to the P1 at 10 am pst but I received P1 at 11:30 am pst again, should I reply again?
I also received an Auto Reply after replying to the original, seems odd