That is an LSM boost, not a trim. I'm not sure if I was correct in putting it there, but it is my working assumption that it physically needs to have some additional boost between the cliff drop & the Arch Hill to A) Ensure that the train makes it over the Arch at all, B) Makes it over at a decent enough speed to provide some kind of airtime, and C) god forbid it doesn't make it over the arch, there would be a way to reset & swing launch it up & over.
Using the figures in the planning document (607ft at cliff, 531ft Arch hill), that 76ft height difference may be sufficient to clear the arch, but with those absurd speeds, unprecedented friction loss & wind resistance, I have no idea if gravity alone will be enough.