avi2tc only processes video, extract audio directly from the raw.
Forgot about an older tool: WMVTIMES.exe
. It produces timecodefiles from wmv files. The latest version also fixes that weirdo first timestamp not being zero.
Also from its output you could confirm that wmv only stores timestamps with an accuracy of 1ms. Seems like mkv2vfr uses a 'diff' value on its own.
On another topic I rewrote my little toy