I have to comment that clearly the documentation needs improvement. It's always the last on the priority list, I realise, but this is really very obscure. I'd read through configure --help multiple times and not noticed this option, and even now the description is highly non-obvious if you didn't already know what you were looking for and what it meant. The line reads:

'--enable-mpit-pvars=list - selectively enable MPI_T performance variable in
                             modules. list is a comma-separated module names,
                              including (Default is "none"):
          none     - No performance info recorded
          recvq    - All message queue-related
          nem      - All nemesis-related
          rma       - All rma-related
          all         - All variables above'

which requires a very close read to interpret the implications. It's not the kind of thing you're going to spot immediately even ex post facto without significant prior knowledge. It's not documented or mentioned anywhere else.

I also think this would more appropriately be a run-time option for mpiexec rather than a build-time option for the toolchain itself. There are numerous situations where I'd want to have performance monitoring enabled for some runs but not others. It doesn't seem to me to be an obvious choice to make it a build-time option, and it would be awkward to have 2 separate builds. In addition there are the MPICH binary installs available for many OS's which ought to have these options available in some form - it would be a surprise I suspect to a user who'd installed from a binary image to find support disabled for certain features that they'd not even been given the option to select.

By the way, just looking through the configure --help output again I notice that at least one option: --enable-error-messages-level, doesn't document what the default setting actually is. There may be others.