On the face of it,
I would say no.
Make life easier for yourself and just run a seperate conduit.
At least then there will be no question of your stuff mucking up anything that has been pre-installed.
Even though we are talking about low-level signalling stuff here, its best to have some sort of segregation, even if for fault-finding purposes down the track.
By that I mean, who hasn't opened up a but of wire troughing and found a tonne of wires all the same colour?
Also with new conduit, you have the opportunity to identify your work as being say "GEN-ANN" along the way.
Just my thoughts.
Let's face it, these days if you're not young, you're old - Red Green