How does the level penalty in the postgame experience tally work?

How does the level penalty in the postgame experience tally work?

Upon completing a mission, experience is tallied out based on a number of
factors. Crew survival, mission skill, and risk factor are among some of
the potential contributors to experience. With most (if not all) missions,
there appears to be a set player level tied to it that, when contrasted
with player levels, can deduct experience from your final tally.
My question is this: Which types of missions (Four Stores, Bank Heist,
Watchdogs, Firestarters) carry which hidden level values with them?
Additionally; How do additional difficulty levels affect this level bonus?
What scale does the deduction operate on? Does it subtract experience for
both underleveled (would make some sense, this could be in place to curb
powerleveling scrubs) and overleveled (keeping some challenge around for
highly leveled individuals) parties?