I'm using an old version of CrocoDash, so the answer might just be to update my checkout... but I created a CESM sandbox that includes ESCOMP/MOM_interface#279 and then set compset="CR1850MARBL_JRA" when creating my CrocoDash Case object and it did not add the MARBL namelist changes to user_nl_mom or create the files that would be specified by MARBL_FESEDFLUX_FILE, MARBL_FEVENTFLUX_FILE, or MARBL_TRACERS_IC_FILE (although it did create OBCs for the MARBL tracers and include them in the SEGMENT_DATA namelists.