If you put the annotations, then the observation is for the live animal at the time it lost the feather or made the footprint or left the exuviae as it eclosed. The date would be inaccurate if you put it as the date you saw the evidence. If you DON’T put the annotation, then it is effectively just an observation of a feather, so won’t affect phenology graphs.
I’ll repeat myself… again! I think we should wait for @tiwane to let us know if this is an actual problem!