Does PolicyPak Least Privilege Manager block Macro attacks?

Partially, but this is by design.
First, Microsoft already has protections in to properly block Macro attacks themselves. You can learn about that here.

But after that, or if you had NO protection in place, when PolicyPak Least Privilege Manager’s SecureRun™ is in place, we will automatically block the Macro from running supported PolicyPak Least Privilege Manager types including scripts, EXEs, MSIs, JARs and more, since the downloadable payload would be owned by the User and not Administrator, Trusted Installer or anyone one the SecureRun list.