Item JSON

Are Item JSON's no longer supported on Bedrock? I have Holiday experimental features on and this command doesn't work:

/give @p iron_sword 1 0 {"minecraft:cooldown":{"category":"attack","duration":2}}

The output I got from the command was component 'minecraft:cooldown' is not a supported component

I got the information from the Microsoft Item Documentation page, and there was nothing said about the feature being unsupported. I think it should be available to use so players can make various custom items with commands.