Possible to code around markers placed on layer when placed as Motion Graphics?

I'm late to the conversation, and don't know much about Premiere, but if I was going to knock something out in AE, it would be text expression like this, where layer markers delineate the completion of each lap:

cur = last = best = null;
m = marker;
n = 0;
if(m.numKeys > 0){
  n = m.nearestKey(time).index;
  if (time < m.key(n).time) n--;
}
if (n > 0){
  cur = time - m.key(n).time;
}if (n > 1){
  last = m.key(n).time - m.key(n-1).time;
  best = last;
  for (i = 1; i <= n-1; i++){
    temp = m.key(i+1).time - m.key(i).time;
    best = Math.min(best,temp);
  }
}
(best == null ? "" : best.toFixed(1)) + "\r" +
(last == null ? "" : last.toFixed(1)) + "\r" +
(cur == null ? "" : cur.toFixed(1))

The best, last, and current times are displayed top to bottom.

You can create a timer that looks a composition markers with this expression:

tMin = thisComp.marker.key(1).time;
tMax = thisComp.marker.key(2).time;
value1 = thisComp.marker.key(2).time;
value2 = thisComp.marker.key(1).time;
et = tMax - linear(time, tMin, tMax, value1, value2);
d = 100;
t = Math.round(et*d)/d;
t.toFixed(2);

You could add Sliders to give you a start and end time instead of using Comp Markers. 

I don't know of any way for an expression in a MOGRT to read markers added to a clip in Premiere Pro. I would have to do some research on that.