A fine alternative to (ab?)using flac files as containers for dts files is to make cue sheets that serve as a metadata "side-file." For example I placed the following text file, which I named metadata.cue, in the same directory as the dts files extracted from Elliot Scheiner's Grammy-winning surround DVD of Layla and Other Love Songs:
TITLE "Layla and Other Assorted Love Songs"
PERFORMER "Derek and the Dominos"
REM GENRE "Rock"
REM DATE 2011
FILE "01 I Looked Away.dts" WAVE
TRACK 01 AUDIO
FLAGS DCP
TITLE "I Looked Away"
INDEX 01 00:00:00
FILE "02 Bell Bottom Blues.dts" WAVE
TRACK 02 AUDIO
FLAGS DCP
TITLE "Bell Bottom Blues"
INDEX 01 00:00:00
FILE "03 Keep On Growing.dts" WAVE
TRACK 03 AUDIO
FLAGS DCP
TITLE "Keep On Growing"
INDEX 01 00:00:00
FILE "04 Nobody Knows You When You're Down And Out.dts" WAVE
TRACK 04 AUDIO
FLAGS DCP
TITLE "Nobody Knows You When You're Down And Out"
INDEX 01 00:00:00
FILE "05 I Am Yours.dts" WAVE
TRACK 05 AUDIO
FLAGS DCP
TITLE "I Am Yours"
INDEX 01 00:00:00
FILE "06 Anyday.dts" WAVE
TRACK 06 AUDIO
FLAGS DCP
TITLE "Anyday"
INDEX 01 00:00:00
FILE "07 Key To The Highway.dts" WAVE
TRACK 07 AUDIO
FLAGS DCP
TITLE "Key To The Highway"
INDEX 01 00:00:00
FILE "08 Tell The Truth.dts" WAVE
TRACK 08 AUDIO
FLAGS DCP
TITLE "Tell The Truth"
INDEX 01 00:00:00
FILE "09 Why Does Love Got To Be So Sad.dts" WAVE
TRACK 09 AUDIO
FLAGS DCP
TITLE "Why Does Love Got To Be So Sad"
INDEX 01 00:00:00
FILE "10 Have You Ever Loved A Woman.dts" WAVE
TRACK 10 AUDIO
FLAGS DCP
TITLE "Have You Ever Loved A Woman"
INDEX 01 00:00:00
FILE "11 Little Wing.dts" WAVE
TRACK 11 AUDIO
FLAGS DCP
TITLE "Little Wing"
INDEX 01 00:00:00
FILE "12 It's Too Late.dts" WAVE
TRACK 12 AUDIO
FLAGS DCP
TITLE "It's Too Late"
INDEX 01 00:00:00
FILE "13 Layla.dts" WAVE
TRACK 13 AUDIO
FLAGS DCP
TITLE "Layla"
INDEX 01 00:00:00
FILE "14 Thorn Tree In The Garden.dts" WAVE
TRACK 14 AUDIO
FLAGS DCP
TITLE "Thorn Tree In The Garden"
INDEX 01 00:00:00
FILE "15 Mean Old World.dts" WAVE
TRACK 15 AUDIO
FLAGS DCP
TITLE "Mean Old World"
INDEX 01 00:00:00
This worked fine in foobar2000, VLC, and Kodi. I'm still having a bit of difficulty getting this technique to work with a DTS-CD in Kodi, but I suspect it's a minor issue. Once I get it working, I'll probably write a script to make these metadata files for all of my DTS-CD rips and (lossy DTS) music DVD rips. While this technique does not directly address cover art, putting a cover.jpg file in the same directory is a decent workaround.