PR #19108 caused some Suspense-related DevTools regressions (more info available on #19368) which we did not catch because of the fact that DevTools tests are only run against the version of React in master.
When using the Swap plugin, it's impossible to cancel a swap once the swap threshold has been met for an item. You can't drag the item back to its original place to prevent a swap. This happens with or without the revertOnSpill: true option.
This package seems to polyfill window.Promise, regardless of whether window.Promise already exists. This is causing problems as we are using and relying on our own polyfill (bluebird.js), but this is being replaced if I call new EditorJS().