When using Knox E-FOTA, does a forced firmware update still ask the device user to agree to the update?

No. The device user will not be asked to agree to the firmware update. This is unlike the Knox Premium API method AdvancedRestrictionPolicy.allowFirmwareAutoUpdate which does still prompt the user to agree to a firmware update. The method for Knox SDK is allowFirmwareAutoUpdate

Because Knox E-FOTA does not ask the device user to agree to the update, you can schedule firmware updates at non-peak times to avoid impacting staff productivity. However, be sure to remind employees beforehand of the device requirements for a FOTA upgrade. Refer the API for forced update in the Knox E-FOTA REST API Reference.