Max Potential First Input Delay is calculated based on First Input Delay (FID). It portrays the maximum time it takes the browser to respond to a user action, such as clicking a button or trying to type something into a form. Max Potential FID can be used alongside Time to Interactive to quantify when your sites and apps can be successfully interacted with.
You can add Max Potential First Input Delay to the Pulse page through customising the Metric History view and set budgets against it.