The manuals states If a time value does not have millisecond precision, the milliseconds portion will be zero.. It looks like time values for {created}, {modified}, and {accessed} etc. do not provide milliseconds. A command like
Rename TO={created|T#MHHmmss}.{ext}
used on a file on an NTFS-drive will always return a time that ends with ,000 even when the lister shows the milliseconds in the various datetime columns.
Will you be looking into this? Some funny stuff is happening here, depending on the T#-template. It doesn't always work, even when milliseconds are shown.