What are the specific things I should be looking for with a dose of 210mg Vyvanse (lisdexamfetamine) every morning?

Wrong dose. The max recomended dose for Vyvanse (lisdexamfetamine) is 70mg. It comes in a 20mg strength too, which is what i guess you're asking about. If you have adhd, that dose would be expected to help you concentrate better, but would make it hard to sleep at night if you take it in the afternoon. Depending on the patient, it might also make you feel a little jittery.
Different Treatment. I am very concerned if you are really taking 210mg of Vyvanse (lisdexamfetamine) at one time. This is 3 times the maximum recommended daily dose and it puts you at risk for increased side effects. I also have concerns that you might be overusing Vyvanse (lisdexamfetamine) if you need that kind of dose for benefit. I would encourage you to get a second opinion and look at other options for treatment.