execute at @s run fill ^ ^ ^.1 ^ ^ ^-.1 minecraft:chest{Items:[{Slot:0b,id:"minecraft:bedrock",Count:1b}]} replace bedrock
execute at @s run fill ^ ^ ^.1 ^ ^ ^-.1 air destroy
execute at @s run execute at @e[type=item,distance=..3,nbt={Item:{id:"minecraft:bedrock"}},tag=!NoKillTag] run setblock ~ ~ ~ bedrock
execute at @s run execute at @e[type=item,distance=..3,nbt={Item:{id:"minecraft:gray_concrete_powder"}},tag=!NoKillTag] run setblock ~ ~ ~ gray_concrete_powder

execute at @s run kill @e[type=item,distance=..3,nbt={Item:{id:"minecraft:bedrock"}},tag=!NoKillTag]
execute at @s run kill @e[type=item,distance=..3,nbt={Item:{id:"minecraft:gray_concrete_powder"}},tag=!NoKillTag]
execute at @s run kill @e[type=item,distance=..3,nbt={Item:{id:"minecraft:chest"}},tag=!NoKillTag]
kill @s