This was a request I brought up in this thread of sandbox options that could be included after update 2.0 that I wanted to expand on with a video sample.
Sandbox mode has been my go to mode when it comes to Jurassic World Evolution 2, as I could pick any building theme, map, and dinosaur, while enjoy park progression with research, expeditions, and the expected challenges of running a prehistoric park. I do think it needs a few more sandbox options such as the inclusion of tax, setting staff+park expenses, challenge mode genetics (fussy + intelligent genes), as well as the occasional urgent player choice prompt to make sandbox more of a free form challenge mode, but one thing that does stick out to me at least is how quiet sandbox mode feels when you progress and increase your park's star ratings.
Simply put, I think it would be a nice toggleable option to have the game acknowledge a park's star rating progression in a sandbox game, as the notifications from the cast of characters on your park rating is a nice update on your progression and a great motivator to keep building your park. It would also be just as satisfying of a feeling to reach a park of 5-star rating with some form of acknowledgement.