I know it shouldn't be included in the command line field, but the command that I tested from the command line is:
msiexec /qn /norestart /i backup2.msi ADDLOCAL=Feature_BackupEngine,Feature_BackupServer,Feature_ManagementTools /L*v %TEMP%\AltaroInstall.log
So how do I get Patch Manager to yield the same results as running this from the command prompt?