redwood page customization

Summary:

As we are moving towards Redwood pages on all the modules, I wanted to understand the possibility of making personalizations in those pages.

Content (please ensure you mask any confidential information):

In classic UI and RUI, we were able to use page composer for adding HTML boxed, custom text box, custom reports etc. How will that work in case of Redwood page.

Example- in the performance document page, we have added a custom BI report which reads parameters dynamically and displays the reports to the employee. Will that continue to work in redwood page or it need to be removed?