Custom structure has generation problem

Hello, I have recently created a new structure for "The End". It is a tower that is supposed to spawn in the "Small End Islands" however I am running into 2 issues.
1. The are spawning way to close, I want them to have around the same spawn rates as End Cities.
2. They are spawning WAY too close to the void. It's supposed to spawn with the other islands I would assume but instead I am running into this issue. -https://imgur.com/a/3RcOjkm