When you create an alias of a movie file, you can charge it in modul8. So you can have two times the same loop (with different name) in media set (the original file and the alias).
The question is : how many file are preloaded in ram when you use the both ? One or two ?
It seems it may be loaded two times (by checking the ram activities) but I am not sure. Surprising no ?
If alias using no more ressources in ram, I'll match effect on alias name. And so I'll can change effect by slide show module...