i worry that this may be too much for undergrad physics majors who may not have had any other astro courses. But I will try to see if i can pitch the appropriate difficulty level

Well, one thing they can definitely do CMB-wise is get the physical scale of the acoustic peak by integrating the propagation of a sound wave in the radiation-dominated early universe, as it expands from the Big Bang to recombination. I wrote such a problem for our Quals once…