[racket] Timing of parallel compile

I'm trying to understand why my compiles are as slow as they are and
see if there are any easy gains to make them faster.

If I just want a serial compile then I can use 'managed-compile-zo'
and look at the compile/cm logger to get information.

But if I want to do a parallel compile, then the manager-trace-handler
is overridden and doesn't log the current-inexact-milliseconds
(instead it just prints things when very-verbose is set).
https://github.com/plt/racket/blob/master/racket/collects/setup/parallel-build.rkt#L280

Is there a way to get this information from a parallel compile?