My idea might cost a lot of money, and may probably not happen (well, at least the second part), but here's my idea:
To conceal the Forbidden Journey building from the ride, there should be a vine area (like USH's version) before you enter through the gates.
In the final drop scene, there should be mist covering up all the T-Rex. Then, right at the top of the drop, you stop (kind of like SheiKra). After 3-4 seconds (with mist appearing in the drop), the T-Rex appears from the mist, and then you drop a second after into the mist.