Ok, I'm slow and just figured out what a huge size difference there is between Topx and Refx files. Some files are actually 6 times smaller, but nearly all are at least half the size of the Topx file. I just converted a couple of files within e-Sword and was amazed at the size difference - with no loss of any kind. So, why aren't Refx files used more often? Would it be possible to make a converter that would be faster than doing one at a time from within e-Sword?
If I understand correctly, there is no extra benefit of a Topx file except that it can be edited. If the file is finished and good, why not make it a Refx file and save all that space? I'm currently thinking that there is no reason to keep a file in the Topx format unless there is still work to do on it.