When trying to use the new Timeline page at our top folder level, the performance comes to a crawl as it tried to load data from all children teams.
The new Timeline page which as GA'ed in August 2021 is initially limited to 2000 items. We have a user story that will soon notify users as they approach 1900 items.
You can use filtering to reduce the amount of data shown and get a better experience from the page. The team is considering the ability to pick which projects are included, hide empty swimlane rows and other performance improvements for subsequent iterations of the page. The team is also monitoring usage of the page to see what works best for the most users. Your feedback is the best way to help shape the development of the page.
In-app feedback is monitored by the Product team.