Is it possible the circumvent trebuchets' hardcoded 80% range by playing around with unit classes and stack units, without the end result being that the unpacked one has 0 height permanently?

Ideally I just want this hardcoded attribute to be gone and instead tied to a resource or new attribute perhaps, but until that’s the case, I need a workaround.

Trebuchets can’t unpack into units with a class other than 54 unless that unit’s height is 0, which ruins what I’m trying to do, so simply setting the unpacked trebuchet’s class to 13 is not an option, as it won’t unpack due to an error message that the construction site is obstructed.

Unpacked trebuchets won’t vanish when built if the according checkbox is ticked either, so stacking a unit on top of them this way is impossible.