I think you will find the signal will never turn green with that command. The AI has to be looking for a trackmark beyond the signal to make it turn green and if there is a "wait until not red" command he will not be looking beyond the signal. The best way I have found is to place an invisible junction beyond the station, have it default to the dead end and protect it with a 04 signal. Doing that the train will enter the station with the signal red and after loading the junction and therefore the signal will change when the train is finished loading and looking for the next destination or trackmark.
Cheers,
Bill69