This issue is still not fully fixed, I still get two video streams when I make positional changes to the graphic subtitles and add ass custom watermark using the following parameters.

 -f mp4
 -c:v h264_nvenc -profile:v high -level auto -preset slow -cq 28
 -bf 4 -b_ref_mode middle -rc-lookahead 32 -spatial-aq 1 -temporal-aq 1 -aq-strength 10 -fdkprofile he -ac 2
 -sn -map_metadata -1 -map_chapters -1 -shanarcmode variable
 -filter_complex "pad=1920:1080:(1920-iw)/2:(1080-ih)/2:black[vv],[0:s:]scale=1920:h=1080:flags=bicubic[sub],[vv][sub]overlay=0:85[vvv],[vvv]ass=logo.ass"
No other filter parameters have been added other than the above. Works fine in older versions.

After using filter_complex, the actual effect cannot be previewed.

In addition, we hope that practical functions can be enhanced in the next version. The value of handler_name is displayed in the audio stream list. Display Track name in subtitle stream list.

As shown in the attachment, although there are two chi languages, one is simplified and one is traditional, and I can't intuitively make the selection I need in the UI. Same problem with audio streaming. Would like to be able to display more information. Thanks.