Well, 33 views and no responses. I can only assume that nobody here had succeeded in writing to the system/app folder to rename those apks. Oh, your battery life must suffer!
Here's a link re: root explorer not working effectively (i.e. no file-names visible):
https://www.mobileread.com/forums/sho...d.php?t=188512
I'm surprised there's not more discussion about it, but that's rooting e-readers for share. It's rarely documented.
Maybe I'll just grope blindly to the system/app folder and mount it. Probably the easiest. Except that I probably tried that and it didn't work. Oh well.