minecraft:equippable saddle item with custom equip_sound does not play the specified sound when saddling entities

Equipping a saddlable item with custom equip sound doesn't play the custom sound – it always play the default sound of the entity

1. Obtain custom saddlable item
   /give @s tuff[minecraft:equippable={slot:"saddle",equip_sound:"block.anvil.destroy",allowed_entities:"minecraft:pig",dispensable:true,equip_on_interact:true}] 1

1. Spawn the desired saddlable entity (a Pig, in this case, but can be a Horse, Donkey, etc.)

2. Equip the saddle by right-clicking on the entity (alternatively: putting it into the saddle slot on a horse)

3. Notice the sound that plays

Expected

block.anvil.destroy (the custom equip_sound set in item data)

Actual

entity.pig.saddle