FFMPEG itsoffset and video delay sanity check

I thought I was going crazy, I have a mkv with audio and video and I have a second audio track I would like to mux in with a positive delay. However when I do it, FFMPEG seems to be changing the other tracks to a negative delay.

`-analyzeduration 2147483647 -probesize 2147483647 -i video.mkv -analyzeduration 2147483647 -probesize 2147483647 -itsoffset 21ms -i audio.dts -map 0:v:0 -map 1 -map 0:a:0 -map 0:a:1 -c copy output.mkv`

Then if I check mediainfo it shows:

`Delay relative to video : -21 ms`

For audio tracks 2 and 3, which are the original tracks. I even just updated ffmpeg to be sure:

`ffmpeg version 2024-10-21-git-baa23e40c1-full_build-www.gyan.dev`

What I found was that the video also has a 21ms start time if you look in ffprobe

`ffprobe -hide_banner -show_entries stream=start_time video.mkv`

`[STREAM] start_time=0.021000`

So since the video stream and the newly muxed audio stream both have a 21ms delay Mediainfo shows all the other tracks, that have 0 delay as having a -21ms delay.

Should I leave it like this or somehow remove the delay from the video so it actually starts at 0ms? Just wondering if it would cause any problems later with something trying to read the file.