Does SF work on time entry? Project time entry? My research yielded nothing.

What you are trying to achieve?

Check the billable checkbox on certain conditions (based on user role).

As far as know it possible. record type = time. set field value action.

Yes, there it is

👍

It's funny, it doesn't appear in the Record Type dropdown list when you're searching for Time WFs, but when you go to create one, it's on the list (defect?)