USB Serial.begin wait to 2.5 seconds (hopefully enough)

teensy3/usb_serial.h

         void begin(long) {
 		uint32_t millis_begin = systick_millis_count;
 		while (!(*this)) {
-			// wait up to 4 seconds for Arduino Serial Monitor
+			// wait up to 2.5 seconds for Arduino Serial Monitor
 			// Yes, this is a long time, but some Windows systems open
 			// the port very slowly.  This wait allows programs for
 			// Arduino Uno to "just work" (without forcing a reboot when
 			// the port is opened), and when no PC is connected the user's
 			// sketch still gets to run normally after this wait time.
-			if ((uint32_t)(systick_millis_count - millis_begin) > 4000) break;
+			if ((uint32_t)(systick_millis_count - millis_begin) > 2500) break;
 		}
 	}
         void end() { /* TODO: flush output and shut down USB port */ };