Give all roles permanent knowledge of their role’s special spell starting right at the beginning of the game. The expectation is that a starting character probably can’t cast it, but will be able to given time.

Once you have learned your role’s special spell, you never forget it.

When you are gifted a spellbook by your god as a prayer boon, the book will always be your role’s special spell if you don’t already know it. (Possibly, they won’t give it to you if you have it identified, or they will give it to you if you know but have forgotten the spell.)

Change rogue’s special spell to knock rather than detect treasure.

In variants that have the Pirate role, this would free up the spell of detect treasure to be their special spell.