scoreboard players add @s[scores={dummy_z=..-512}] dummy_z 512

execute unless score @s dummy_z matches ..-256 run function bd:control/warp/warp_to_saved_coords/z/n128
execute if score @s dummy_z matches ..-256 positioned ~ ~ ~-256 run function bd:control/warp/warp_to_saved_coords/z/n128