QS:Time limit warning display time
From LimeSurvey Manual
Time limit warning message display time (time_limit_warning_display_time)
It sets for how long the time_limit_warning_message is displayed before it is removed/hidden from the screen. By default, if the time_limit_warning_message appears, it will remain visible until the countdown timer has completed the countdown. If a value greater than zero is introduced in this field, the message will be hidden after that many seconds.
This setting is applicable only if the general time limit setting is activated. This setting also exists for a second warning message.
time_limit_warning_display_time: 10 = The time limit warning message will disappear 10 seconds after its moment of appearance.