control animation angle in a précompte

If you have an expression in a precomp that's looking at layer markers on that precomp layer in the main comp, you'll need to adjust the expression to compensate for a non-zero start time of the precomp layer. It will end up looking something like this:

L = comp("Main").layer(thisComp.name);
m = L.marker;
val = value;
if (m.numKeys > 0){
  n = m.nearestKey(time + L.startTime).index;
  if (time + L.startTime < m.key(n).time) n--;
  if (n > 0){
    val = parseInt(m.key(n).comment);
  }
}
val