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Yeah, that's what it looks like I may do. A single roller on 'low' will jump a cart across a single tile pit and still make a turn immediately after it.
How about an "airlock pit"? Side view:
#########
___ _ ___
__+^#^+__
#########
Top view, level Z:
#########
=== = ===
#########
Top view, level Z-1:
#########
+^#^+
#########
From the cart perspective, it has a 1-tile pit to jump, a tile (or more if needed) of "middle" track, and another 1-tile pit. The "middle" track has no way to be accessed by dwarves (or anything else that doesn't fly or jump), and should probably be all rollers. Any dwarf, animal, etc. caught on the lead-in track will be knocked (or dodge) 1 level down into the pit, onto a pressure plate which opens a door leading back the way they came (into their home pod/burrow). Hopefully, even in case of odd errors such as the cart ending in the pit or a dwarf breaking their legs, since the only place they can land is the pressure plate opening the door, someone will come collect the cart, rescue the dwarf, re-pasture the animal, etc. Even in cases of a failure into the pit on each side somehow, the two sides are separated by solid wall at their level.
Can you power rollers from "above"? If so, this would be compatible with an above the ceiling power grid; Z+1 is mostly solid but has a gear any place you need power on Z, and Z+2 has axles strung as needed (quite possibly running above your cart tracks by default).