In the last chapter of the Lam Rim Chen Mo, Lord Tsongkhapa says to develop experience in Bodhicitta and confirm it "with the rite" and then study the Bodhisattva deeds, what to discard and adopt, and to take the vow of engaged Bodhicitta.
So there are two separate Bodhisattva vows? One for Aspiring and one for Engaged? What deeds? What should be discarded and adopted?
This is an novel position of Tsongkhapa's. In general, in the other schools it is sufficient to take the bodhisattva vow in teh Madhyamaka tradition. But in Gelug, it is considered important to also supplement that with the Yogachara system.