Having the symbols driven by segments?

I like all the improvements you did the last few months. It is getting really great! I have a request regarding symbols.
Currently, they all show up at the beginning and disappear at the end. Would it be possible to have symbols attached to segments and have them appearing when the segment becomes active? That way we could stagger them over time and highlight some specific event during the progress of the tracks…Also, having an option to have them staying until the end of the clip or the end of the segment would be great. What do you think?