Hope This Helps
 

Moving the starting gate has no bearing on the actual distance of the race.

The race DOES NOT START at the gate, it starts at the pole or whatever distance marker is.

The starting gate is placed before the start, sometimes quite a bit but there is always a run up to the actual start where the clock starts. Which makes moving the gate around immaterial to the actual distance run.

Which is why the gate movement was quoted as 10-25 feet but only because of course wear not in an attempt to even out distance due to rail movement.