Just to close this out, I'll continue to use MP3tag for the tags, but not to rename the files.
I have found that the file renaming utility I use, Winsome File Renamer 8.0, has the ability to rename from a list. Using cut and paste, and a directory printing utility, I can build a list in a table in Word, with the old name, new name, and folder path. Then convert the table to tab delimited text, then tell Winsome to use the new text file. It did exactly what I wanted; simply rename the MP3 files. I'll continue to use MP3tag for the tags, including Convert -> Text File - Tag to add the Title and other tags, but not to rename the files themselves.
I am converting old vinyl LPs, so the whole process starts with a track list from the back of the LP sleeve. Some are long descriptions, so a simple track list is created from the track descriptions. The track list is used as the MP3 Title, in plain english. I use the MP3 Title for the filename, but replace all spaces and punctuation with '_', and add a track number, 01, 02, 03, etc., to the first of the filename.
You could just as easily create a user defined field in MP3tag (e.g. %new_filename%) that holds the new filenname and then use the function Converter >Tag-Filename with the mask %new_filename%
This would save you the bother to open 2 other programms and enter 3 times as much data as MP3tag already knows the old name and the path.