code: def applyUserPars_steps(configObj, input_dict, step='3a'):
      
      step_kws = {'7a': 'final_wcs', '3a': 'driz_sep_wcs'}
      stepname = getSectionName(configObj,step)
      finalParDict = configObj[stepname].copy()
      del finalParDict[step_kws[step]]
  
      # interpret input_dict to find any parameters for this step specified by the user
      user_pars = {}
      for kw in finalParDict:
          if kw in input_dict: user_pars[kw] = input_dict[kw]
      if len(user_pars) > 0:
          configObj[stepname][step_kws[step]] = True
docs: Apply logic to turn on use of user-specified output WCS if user provides
          any parameter on command-line regardless of how final_wcs was set.