Starting July 30th, you will no longer be able to log in to a Curse account that was not merged with a Twitch account. If you have not yet merged your Curse account with a Twitch account, please do so here! Otherwise, your account and its content will be inaccessible.
Amplified is programmed to make an exception for River, Beach and Ocean biomes and will not apply the transformation to them, but Customised does not have this exception. On the Customised variant of your seed, Oceans and Beaches will have jagged pillars which occur frequently. Other than that, it is the same.