[Guod3]

Thanks so much for your input.
So now have 2 parameters:
kEffectType (no gui control)
kEffectTypeSelector (with gui control)

*pseudocode*
in OnParamChange(int paramIdx):
.
.
case (kEffectType):
    send out Effect type CC to midi

case (kEffectTypeSelector ):
    if value of parameter EffectType != EffectTypeSelector (user has acted?) 
          set all params to default
          assign value of EffectTypeSelector to EffectType
          call  OnParamChange() for all affected parameters

Is this like what you had in mind?
Thanks again.