The present application discloses systems, methods, and computer-readable media that can dynamically control a number of provider devices operating in a prioritized-dispatch mode by determining a range of prioritized-dispatch-mode slots for a target time based on differences between value metrics received by provider devices operating in multiple dispatch modes and sending availability nudges to provider devices based on the range of prioritized-dispatch-mode slots. For instance, the disclosed systems can generate a threshold-noticeable-value difference between historical value metrics received by provider devices while operating in a prioritized-dispatch mode and in a basic-dispatch mode. Based on the threshold-noticeable-value difference, the disclosed systems determine a range of slots for the prioritized-dispatch mode during a target time period for a geographic area. Based on the determined range of slots, the disclosed systems can transmit prioritized-mode-availability indicators to provider devices to indicate varying levels of availability of the prioritized-dispatch mode for the geographic area.