Vedanta is often equated with yoga or mixed up with it. The Vedantin does not fear duality or bob in an out of identity with Brahman. When I understand clearly that the real me is identical to Brahman, no experience can change that understanding of myself. I cannot forget it. Even madness does not destroy that knowledge.
Patanjali yoga can provide steadiness of mind, just as does karma yoga and devotional practice.
All are preparatory to gaining knowledge from a qualified teacher. Some people say that there are many paths to the goal, that there is an approach for every kind of personality. It is true that people can start their spiritual journey in many different ways but that does not say that there are many ways to come to know the truth about the self. For every knowledge, there is only one way to know it. To know the fragrance of the flower, one must use the sense of smell.