This is complicated to describe, so I'm going to use a not-so-great example. In PowerPoint you can put "placeholders" on the master pages. If you make a change to the position of the placeholder and update the slide everything moves into the correct position.

I'd like to be able to do something like that with text frames on the master in InDesign. The problem I'm having is that because I can't have two "primary text frames" on the master, I have to command-shift click to get the second text frame to be active. Once I do that, however, I can never reapply the master, because if I do, the text in the command-shift-clicked frame will disappear. The text in the primary text frame will not.

Is this something you guys can fix? I understand the idea of primary text flow, so you can't necessarily link things automatically in the second frame - although maybe there could be a way of marking the frames so that they do flow properly.

The issue is, I'm working on documents for the pharmaceutical industry and they need to run Important Safety Information thoughout the document. This frame would be at the bottom, while the other primary text frame would be at the top.