Is there any reason why the ride system/operators would keep a train on the back brake for substantially longer than necessary after the other train is dispatched from station to lift?
If so, then it might be a benefit to have the block brake instead of a trim. Assume for a moment that a train reaches the top of the lift while the other train has not yet cleared the back brake. Without a block brake, the train on the lift must stop. From a rider comfort perspective, stopping a train at the top of the lift -- staring away from the entire park and therefore unable to see or understand anything about what's going on -- is less desirable than stopping the same train farther down the line at a lower elevation; on a nearly horizontal section of track; and looking back in the rough direction of the station, give or take, so many riders have the advantage (real or perceived) of seeing the park, people, and station while stopped. Also, the block brake stop occurs several seconds later than the lift-hill stop would, which gives the back-brake train more time to clear that block in the first place.
That all depends, however, on the existence of some reason why that back-brake train wouldn't have moved into the station as soon as the train ahead of it was fully on the lift.
The station + lift together don't comprise one single zone, do they? That wouldn't make much sense, and I don't recall waiting a curiously long time for another train to arrive at the boarding platform after a previous train left -- which would be the case if [station + lift] were zoned together.
Dunno.