In the Tesseract FM, you'll have a limited number of Super Manager slots you can use. These slots are subject to specific limitations, such as the rarity. You'll also need to choose your Super Managers carefully, as once confirmed, you cannot change them until you complete the mine.

You can upgrade the Tesseract to unlock more Super Manager slots through the Tesseract panel, allowing you to use more of your Super Managers as you progress.