The letters page still allows one to begin marking letters as incorrect before starting the timer. Revert back to how you had it so that the enumerators are forced to start the timer in order to see the letters on the screen and to start marking them incorrect. I was able to mark as incorrect several letters, and then choose "next" to move on. The only error message it gave me was that the last letter was not selected, it did not tell me that I had failed to use the timer.
The letters page still allows one to begin marking letters as incorrect before starting the timer. Revert back to how you had it so that the enumerators are forced to start the timer in order to see the letters on the screen and to start marking them incorrect. I was able to mark as incorrect several letters, and then choose "next" to move on. The only error message it gave me was that the last letter was not selected, it did not tell me that I had failed to use the timer.