Given the change to how bootstrap processing works in 2020.x and Spring Boot 2.4 the docs should explain the change in a callout so that readers know that something important has changed that will break code. Maybe adding a callout in the Client Side Usage section explaining the changes from boot 2.3 to 2.4 will help a lot of users. For users migrating from 2.3 to 2.4 this is a common issue that trips up folks.
Comment From: spencergibb
typically release notes are where upgrade instructions go.