Ability Scores Above 18

As I gear up to run a DCC RPG campaign, I've been tinkering with some optional rules I want to add to my game. One of them is a mechanical benefit of ability scores above 18. Rather than simply tack on an additional +1 bonus, what if that score had a bigger impact?

If an ability score is increased above 18, either temporarily, magically, or permanently, the player may choose one of the following abilities:

• When using any ability rooted in this stat, the player rolls +1d on the die chain
• When using any ability rooted in this stat, the player rolls 2d10 instead of a D20
• If the stat is Strength or Agility, the player may re-roll damage rolls
• If the stat is Personality, a Cleric may re-roll the damage healed from their Lay on Hands check
• If the stat is Intelligence, a Wizard or Elf may re-roll their spell damage 

Players must accept the second roll, even if it's worse. If a character has more than one stat above 18, the player must choose a different ability for each. Should an effect reduce the ability score to 18 or below, either temporarily, magically, or permanently, the character immediately loses access to this ability.