Other users are hereby welcomed to vote if this option should be explicitly documented in one of upcoming updates.As an infrequent and mostly indirect user of growisofs i vote for full documentation of all options which are functional.
Well, there always will be reservation for undocumented options. Some might be deprecated, some might be introduced to address some particular problem and might merge in more meaningfull option. It's more reasonable to formulated as "all supported options." A.