I would also love this functionality. Also, and maybe I'm confused by
the wording, but check out the last piece of info on this page:
https://experienceleague.adobe.com/docs/workfront/using/administration-and-setup/customize/custom-forms/add-calculated-data-to-custom-form.html?lang=en
Automatic updates of calculated custom fields Calculated custom fields
on an object recalculate automatically when the following things happen:
-Something on the object changes, such as a daily timeline calculation...