It doesn’t send the data from the gap because the ModularSensors library simply doesn’t have that functionality. It doesn’t attempt to re-send data. The data should be on the SD card, as long as the battery was still high enough to log.
I would really love to have that functionality in ModularSensors, but it’s not simple to implement and I just haven’t had time. If you do have time, I’d welcome a pull request!