CMTrace is a great tool for troubleshooting deployment issues from within WinPE, no doubt about that. It makes errors and warnings clearly visible in thousands of lines of markup logs.

Adding CMTrace.exe to your winpe.wim is easy:

C:\> imagex /mountrw c:\winpe_x86.wim 1 c:mount
C:\> copy /y c:\tools\cmtrace.exe c:\mount\windows
C:\> imagex /unmount /commit c:\mount

C:\> imagex /mountrw c:\winpe_x64.wim 1 c:mount
C:\> copy /y c:\tools\cmtrace.exe c:\mount\windows
C:\> imagex /unmount /commit c:\mount

You should also create a package that copies these files to the %SystemRoot%. This will make CMTrace available throughout the life of the task sequence.