BGP2P sticks have a fused extension. I have personally had to cut one down, so I know this from experience. I can also say that my BGP2P is noticeably lighter than my 1X 3.0 at the same length, even with a larger P10 vs P88 blade. So the Pro Stock ADV is still lighter than a Pro Stock 1X Lite.
Edit: I just went and found what I could of the extension I cut off. The pieces I found are about 5.5" long, which account for the 4" extension and an extra 1.5", but there is still some of the tenon from the extension in the stick. Those 5.5" pieces weigh 39 grams. It's also not all of what I cut, I'm still missing about 1/4-1/2". So the extension plus the epoxy used to fuse it in could easily weigh most of that 60 grams.