I noticed that the wwh*.tmp files are created in my work computer, but not in my home computer.
I did some more testing.
I changed the VeditTempDir setting to C:\APPS\vedit\temp.
It had no effect. The files are still created in %TEMP% directory.
I thought maybe it has something to do with instance control, but changing the setting had no effect.
Then I noticed that the .tmp files are not created if the File Selector panel is not displayed when Vedit is started. If I open the File Selector panel later, then the .tmp file is created (1-2 seconds later).
Maybe this has something to do with network drives that have been mapped to a drive letter. (I do not have network at home.) So maybe it is Explorer.exe that creates the tmp files.