Working with old DVD media, I was trying to load into the timeline. I started by "import DVD media" in Vegas -- it worked but broke it into about two dozen small clips with tiny blips between them.
I started going down the "merge the .VOB files" route with FFMPEG and in the process tested dragging the .VOB files into Vegas directly. Was confused at first that the VTS_01_1 file was the full length of the show, and then there were still the VTS_01_2, _3 and _4 files that seemed to duplicate content.
And then I realized... Vegas was smart enough to realize the _2, _3 and _4 files were continuations of the _1 file and auto-merged them on the timeline! Looking at Project Media it shows the _1 clip having the length of _1+_2+_3+_4, while still showing the original _1 file size. It's a bit confusing to see, but I'm happy in the end with how it was handled.
Sharing this info here in case anyone else runs into similar need to import DVDs still.