Harmy, i see that you are having the same flickering problems i was with the crawl in after effects. Well i did manage to cure a lot of it before i went down the 3DsMax route. If you are doing your project in 1080p then you will need to create the crawl in 4k then scale it back down to 1080p outside of after effects because it has a really bad scaler. Now because you are using a 3d layer you should be able to use depth of field to give the text a slight blur as it recedes into the distance, which should cure most of the flickering problem, although at 4k you might find that there is hardly any flickering anyway, but this depends on the quality of the text being used. If your text is a transparent image then you could always try edge blur if depth of field doesn't work. Other things you could try is by adding an extra layer of the text crawl underneath and mask the bottom layer so that the bottom blurred layer only starts to show as the text is starting to flicker (which would be the upper portion of the text to start with)

Hope this helps