Shooting down once more albeit with a bit of reason, I would say that you might want to consider USH just being...USH, it's own park and not having a second gate due to the restrictions of the property.
Doesn't mean there aren't options for expansion, as noted before Falls Lake/Jupiter's Claim/Transportation Lot is one such area for USH growth and expansion (but there are a myraid of elements that hinder and reject a notion from happening). When they do a proper expansion of the park, I'd say to look at SS16-24 and the Rehearsal Stage (and not the Backlot Cluster that has been often speculated/rumored (and not the Bud Westmore building either).
They still got room to go, with The Simpson's contract up in 2028, Parisian Courtyard being a viable venue for a new attraction, and as I have exasperated: SS16-24/Rehearsal Stage.