Is it possible to add islands via island ID?

[MCXPStudios]

While looking around online, I found someone talking about a way to view an Unimplemented island by using Island IDs, and I was wondering if it'd be at all possible to use one of the programs to access it.

(Also unrelated, just also kinda curious what "DivingFlipper" is.)

[Sapphire645]

Diving Flipper is an unused item/accessory. It allows you to swim by holding the jump button underwater. It steers a bit awkwardly.