Disable manual hourly rate edits for employees on grade steps

We are using grade steps for hourly employees and would like to prevent manual edits to the hourly rate when an employee is assigned to a grade step.

The goal is for the hourly rate to be system-driven based on the configured grade step rate, rather than allowing users to override the amount during transactions such as Change Assignment or Change Salary.

Has anyone successfully configured this using salary basis, grade step rates, or experience design studio? Any recommended or supported approaches would be appreciated.