Based on documentation Use the homepage The starred page is saved along with the team (portfolio, solution, program, or team) and time increment (strategic snapshot, program increment, or sprint) sidebar selections.

Starred

Star pages to access them quickly from the homepage.

To star a page for later, navigate to the page and select the star Star icon next to its title in the upper-left. The starred page is saved along with the team (portfolio, solution, program, or team) and time increment (strategic snapshot, program increment, or sprint) sidebar selections.

However, when the user starred the page for reports or snapshot with Extra config, the extra config settings are removed.

Here is the example with the Work Tree report;
Step to reproduce

1. Filtering with Snapshot A
2. Click on Extra Configs, add 'Theme1' to the Themes section, and then click 'Apply'. Set the page as Starred page.
3. After closing the tab and returning, you will find that the Extra Config remains intact.
4. However, upon signing out and logging back in, if you navigate to the starred page and check the Extra Config, you will notice that the previously saved theme has been removed.

Expected result: when the page is saved as Starred, Saved Extra Config setting as well.