When the player is holding a weapon like a drawn bow or a loaded crossbow (Compatibility could be determined if Fabric or Forge has a standard class for this) , the camera zooms in closer to the player like many games with this camera perspective do. Similar to how Leawind's Third Person does it.

Thanks for the suggestion. This can already be done using the config option camera.offset.multiplier.aiming.multiplier_offset_z.