Besides these two main reasons, they have an innate ability that helps them quickly gain mastery of their divine abilities. So they don't need to risk their lives for progress.
However, they could always risk the lives of their slaves. They don't care if their slaves think they are someone else. As long as their slaves become puppets, their identity as puppets will remain set no matter how many memories they have.
They gained this confirmation after testing the option on their slaves. They bought memory fragments from legendary telepaths in the Mindscape and discovered that as long as their slaves are puppets and they support their slaves mentally, their chances of losing control instantly become drastically reduced.
As for the matter of dissociative disorder, its effect can also be minimized by using their Hypnotize divine ability. So all in all, the worst consequence is their slave losing control, which doesn't affect them much.
