I have team members with part time availability, as specified in their Resource Management profile. Smartsheet allows me to schedule tasks for the days they are not working - the sync to Resource Management then displays "100% allocated for 0 Days" - the 0 days is due to this being a non-workday for that team member.
Furthermore, syncing non-working days for individual team members should be extended to the Public Holidays - I need to specify these in Resource Management (Official Holidays) and in the Smartsheet Project Settings (Non-Working Days). I do not see the point in needing to specify non-working days in two locations.