Is there flexibility in place for shift workers (think FIFO, 2 weeks on 2 weeks off, etc. type scenarios) with respect to ArcGIS Online User ID's? Providing ID's for all field workers when they only work 2 weeks out of every month is hard to swallow.
Disabling an ID still counts towards your total members. You could delete and re-add members. Both of these methods sound potentially painful.
Is there an Esri option or does anyone have any tips on managing this?