I just spent a few hours tracking down an odd rendering issue after upgrading from 5.3.3p3 to 5.4.0p1 and unfortunately this looks like a show-stopping bug (and we'll have to downgrade back to 5.3): A projector will render all of its affected objects 2x if there are any alpha blended materials visible on screen. You can see this easily in the frame debugger (does not happen on 5.3.3p3). I've submitted a bug report. If anyone wants to see this I've attached two projects (they are identical with the exception that one is meant for 5.4.0p1 and the other is for 5.3.3p3). You'll see very different (and correct) behavior in 5.3.3p3.