There are some trouble with the advanced file opening dialog.
VLC can open a few files at once and proposes set advanced options, but they are applies to all files. So, if I have 2 or more videos with separate sound track, there is no way to add they in one approach. I think, the option, which allow to play back an another media file in parallel to the primary, should be applied to the each primary file singly, and also should be activated when I choose a file in the files list which contains already selected files (the subtitles options should behave by the same way). This will allow me to open this dialog only one time and chose all the files I need to watch, and select subtitles and separated sound tracks for the each file, at once.
Also all advanced options could do the same. Or it could contain an additional tick, that allows to apply advanced options to each primary file.
Best regards.