Just wanted to chime in that I'm experiencing the exact same issues.
From another thread a technician posted that it's because of the 'cloud services integration with explorer' that they restart Explorer.exe. What a crock.
Windows Installer has had restart logic built into it for years, restart logic that is completely controllable and compatible with any of the major deployment systems enterprise would be using.
Why in the hell would you restart Explorer.exe? It just makes absolutely no sense.