Does anyone know what the "difficultyHardforkBoundDivisor" parameter refers to? I don't find it in any of the glossaries I know.
I find there tends to be a lag in glossaries and wikis being updated with new information.
/// Difficulty param after the difficulty transition. pub difficulty_hardfork_bound_divisor: U256,
In the answer to your other question I also outlined how this value is used in the difficulty calculation.
For a clearer answer on whether you actually need these in your private chain spec (I don't think you do), you should probably go straight to the horse's mouth and ask on the Parity Gitter channel.