After experimenting, I have found that quitting the game before a cutscene and manually entering the next stage is several seconds faster than waiting for the cutscene to play out:

As far as I can tell, the category rules don't prohibit this. One possible concern is that this would make splices easier to hide, as the score and timer are reset when the game is quit. However, one could theoretically count the fish that the player eats during the stage and compare it to the Food Bank count displayed at the end of every stage for consistency. I want to make sure that this method of skipping the cutscenes has the OK of the community and moderators before using it in runs.