My take on this PR basically falls under my (positive) take expressed in the corresponding PR for appfwk: DUNE-DAQ/appfwk#351.
Having said that, one nitpick: I notice that in DFOModule_test.cxx that the configuration transition got simplified in the Commands test, plus perhaps it would be in the spirit of this PR to remove "_json" from the variable names.
Originally posted by @jcfreeman2 in #430 (comment)