Show loading indicator while post login action or lazy migration scripts are being executed

Went through entire documentation and I just can’t find anything that auth0 provides for showing loading indicator on the new universal login page while post login action or lazy migration scripts are being executed. Is there at least any workaround for this, maybe injecting js script in the custom login page ?

from the other side if the user refreshes the browser in the time of authentication the state will become invalid, but if I need to provide some heavy logic in lazy migration script that can take 3-4-5 seconds and the user at least does not see loading indicator that something is processing its very natural to hit the refresh button

For everyone that are trying to achieve same goal, only way that I managed to present some loading indicator to users is outside the widget, by providing custom script in the page template, that can look something like this: