Hey v-null! Found a bug.
When changing the bust between two dialogue elements in a cutscene, the game doesn't do the transition animation based on the element shown previously, but on the previous element numerically.
What I mean is when Element1 links to Element3, then Element3 will do the bust changing animation based on what is on Element2 instead of Element1. I noticed it when using choice dialogue, but it works on normal dialogue too. I found a workaround by adding an extra element in front Element3 that isn't linked to by anything and is using the correct bust.
Edit: On a second thought if you are not planning to add a button to manually turn the transition on , it might be a good idea to keep this bug in. The workaround I mentioned could be used for the same purpose, while keeping filenames consistent and not having duplicate files.
Another bug I mentioned on /htg/, but you might have not seen it is that lasers can kill the player during cutscenes. Aim a pulsating laser at a goal, move onto the goal when it's not firing and you'll die in the middle of the cutscene when it shoots again. Might be a good idea to make it so the cutscenes pause the game.