You’re double compressing your videos – once when you export them as H.264 out of After Effects and then again in Adobe Media Encoder or whatever other program. Try exporting out of After Effects as an animation or ProRes4444, then give Handbrake a try; it uses a better implementation of the H264 codec. It might give you problems when trying to set the size at 1440×810 though, not sure. If your file is 10 seconds and you’re shooting for 6MB, calculations show you’re going to want a 4.6-4.8 bitrate. Then set the x264 tune drop down to animation.
@ericstrand11