There are 2 large loose blocks on Overhanging Layback that are right over routes.
1 - 2nd pitch - on top of the flake at the bulge below the final roof. If this block falls it will land at a popular part of the Mac Wall that is often top-roped. This rock looks like a good handhold or foothold.
2 - 2nd pitch - I found this when I went around the corner to try to find an easier way to get to the bulge below the final roof. The terrain is a little easier but as you go around the corner there is a large loose block that will be at foot level. If this goes it will hit the 1st pitch of Overhanging Layback.
Other than these 2 loose blocks, P2 with Swain's variation is stellar and highly recommended if you are solid on 5.7 roof climbs.
Thought is the ruler's chief enemy - Napoleon