I just went to test a new route starting with joachin and it happened...

Pumpkin has a double jump and dash in the air, which makes him have an advantage on the steps of the dark palace, has that spin attack that is superior to sapphire and inferior to ruby, so you can complete dark palace quickly even without the green orb ...

also is possible to drop heart repair on some enemies in the dark palace, which saves you about 30 seconds easily