In recent years, there has been an explosion in the number of papers dealing with "cylindrical" PS-b-PMMA, for nanoscopic template or similar applications. This paper deals with two aspects of these systems. One is the detailed shape of the cores, i.e., the degree to which they are actually cylindrical in the hexagonal unit cell, as well as the nature of the core corona interphase region. The second one relates to the use of fluorescence techniques to study these interphases, including whether or not one needs to consider energy transfer from one cylinder to neighboring ones. We approached these questions with numerical self-consistent field theory plus simulations of energy transfer based on them, and we examined two systems: one which mimics "typical" experimental systems at weak to moderate segregation, and one chosen to explore the limits of very weak segregation and polymer composition where the effects of interest could be maximal. In addition to providing basic information about the system characteristics, the results provide practical guidance on using the assumptions of cylindrical symmetry and no intercell energy transfer.