There is a standard path that runs directly from the end of the Treetop Monkey trail through to the TOTE, which skirts between the tiger enclosure and back-of-house native bird breeding facility.
I could see the Tiger enclosure being reconfigured for gorilla, and tiger moved around near the barn potentially - probably wouldn't be the solution but I could see the path potentially being used, or the Treetop Money trail being extended above it.
Treetop Monkey trail is probably my favourite part of the whole zoo, and I for many years have liked to imagine it being extended further, even if it were to be a continuation that included more aviaries, and other non-primate species. Sloth maybe, or smaller rainforest cats...
In fact if this treetop trail did continue along that trajectory, it could then swing left towards th first paddock, giving a higher view of a potential orangutan/gibbon into an expanded lake with two islands, with more treetop exhibits continuing towards a descent at the exit of the Butterfly House. and a second Gorilla bachelor enclosure based in Man Jai's paddock, or the matriachal paddock.
the matriarchal paddock could be then made for Spirit or Kermode bears, as they are also found in rainforests
The trail at the other end once it loops to the current Orangutan enclosure, could cut back across past the island exhibit, and tap back in finishing with the tiger and otters.