I understand you'd like to plot the individual viewports on a layout tab as separate pages.  Unfortunately, that's not how layouts/viewports are designed to work.  The layout tab represents a virtual piece of paper, intended to provide an accurate representation of what your plotted page will look like.  Viewports are merely windows into the Model tab, and as such are just elements to be placed onto layout tabs, in the same way as any other paper space object.  Certainly, as you suggested, you can window each viewport for plotting purposes, but there wouldn't then be a way to send all of them to your plotter at the same time.

I apologize that I cannot provide you with a solution to produce the exact result you're seeking in this case;  AutoCAD is just not set up to do that.  Please let me know if you need more information or further assistance with this issue.  If you do not need further assistance, you may close this Service Request through the Subscription Center, or if you let me know, I can close it for you.