Has anyone built a scenario that automatically adds vacation hours to a user's timesheet after they have added time-off to their personal time-off calendar?

We currently have log time to future dates turned on in timesheet preferences, but leadership is asking that to be turned off, with the exception of vacation days, so those hours can still be entered in advance. If we can automate hours getting logged as vacation based on time-off calendar entries, the Fusion scenario could backdoor the future task dates setting (I think), while also making it easier on the users, so they don't have to update the calendar, AND log time on their timesheet for the same dates.