The calculation of time stationary may be inaccurate;
If the chart above was used, GPXIngest would calculate a stationary time of 20 seconds ((30 - 20) + (40-30)) .
However, during (at least some of) the 10 seconds between 20 & 30, the vehicle would have been decelerating.
Really what needs to happen, is we need to look at whether the last speed was 0, and consider the block moving time if not. So the car in the chart above would have been stationary for 10 seconds, and moving for 30