"in book mode"- No it will not be possible (Keyboard shortcuts are different).
In the Book module-
Select the photo on a page, Press keyboard [E], Now you have access to Metadata and Edit-in Ps.
Note: that [Edit in] Ps a raw file photo may make a new derivative image that appears in the Book Collection, but not replace the photo on the book page.
Return to the Book module by [Double-clicking] on the Saved Book Collection or keyboard [Cmd + Opt + 4 ]
Regards. My System: Lr-Classic 12.3 Photoshop 24.5, ACR 15.3.1, Lightroom 6.3.1, Lr-iOS 8.0.8, Bridge 13.0.3, Windows-11.