Well, the rule as stated there is a recommendation to possibly change “exceptional rolls” to have different effects. It talks about rolling a 1 and 20, but I’d say DMs should probably just use the Pathfinder option of getting 10 points higher or lower than the DC. It just makes so much more sense, although the advantage/disadvantage system doesn’t really work for this as well as the Pathfinder system, which actually adds to your roll.
At the end of the day, everything in the book is a guide. You should throw parts away that don’t work and add things that do. Regardless though, the rules of Pathfinder 2E need a lot less modification to work as you’d expect.