I discovered a glitch that could potentially save time in Any%. If you jump off the ledge at the start and hit the death barrier underneath the mouth sometimes you will respawn on top of the mouth. From there you can run across the top to the other side. Sadly this won't work every time (I think it has to do with the mouth cycles) and I'm not even sure if it saves time. It is definitely worth looking into though.

I'm not sure what you mean by emote, but it doesn't really matter. This setup is made obsolete by the improved one shown to me by zir0nic and supercrazestar. Kill youself in the menu during the opening cutscene and then press skip after about a second and you spawn on top of the mouth much faster.