Milliseconds issue while exporting folders with many tracks

I´m trying to export a lot of audiobooks - especially their total length.

I tried %_length_seconds% for each track (summing them up afterwards).
I tried %_total_time% for each folder.

But the more tracks there are in a folder the more WinAmp and MP3TAG disagree on the total length!

Example - total length of an audiobook consisting of 117 tracks:
MP3TAG: 19:27:28
WinAmp: 19:26:39

It seems to be caused by different treatment of millisecond-fractions of the length:
WinAmp seems to cut away any milliseconds: 0:09:10.551 -> 0:09:10
MP3TAG seems to round up / down correctly: 0:09:10.551 -> 0:09:11

These differences per track then sum up :frowning:

Is there a way to export the track-length exact to the ms?
Then I could cut away the ms afterwards...

Or - even better - is there a way to make MP3TAG ignore any ms on export?

Best regards and thank you in advance!
Hori