Block location exploit from abusing model element rotation
The exploit
It is possible to make models, particularly those of blocks, have elements exist visually far away from the actual block. This relies on specifying rotation parameters.
Consider applying such a model to a coveted block such as diamond ore, and you have an easy way of locating such blocks which would otherwise be completely obscured from the player simply by using a resource pack.
Indeed, this hilarious exploit can be combined with MC-259190 to make using that exploit considerably easier. Neither require any game modifications.
Exploit demonstration
Attached to this ticket is a resource pack with two models using this quirk: one "large" model for diamond ores, and one "huge" model which is applied to spawners and ancient debris.
The "large" model consists of several large cuboids, all of which make contact with the central block. As a result, if you see one of these cuboids protruding through the ground, you know it's connected to an ore seam, possibly hidden. How much of it is protruding is a simple indicator of how buried the block actually is.
The "huge" model is the large model, plus many other cuboids, which are marked in pink. This causes the model to protrude out by eighteen whole blocks. If you see any pink cubes while exploring, you know that said cube is seventeen or fewer blocks away from an ancient debris block or a spawner, and that being inside one of said cubes means you're perfectly axis aligned with it and should continue in that direction.
How to fix
Instead of clamping the coordinates for where an element can be rotated around, it's probably a better idea to truncate any triangles which protrude outwards from a 3x3x3 cube centered on the central block with one of these models.