Well here's the thing. Demuxed files from Streamclip are being re-encoded even with options set to no encode.
VOB files from some DVD's which are lower bitrates are processed by Toast without reencoding, in fact quite a few.
And when I ripped an entire DVD to one TS folder there is no way to select chapters within a title so that is anther wasted exercise with the media browser, only titles can be selected. It was a 4 hour title and I got one title, four hours. Which incidentally took 10 minutes to bring into Converted Items with its XML file and I could have just dropped the TS folder in to Toast instead, as that amounts to the same thing.
I presume in some sort of response to the recording industry the VOB to DVD option has been cripped though since a TS folder can be used instead there seems to be little point to disabling VOB use. So if I had such designs, I'd rip a DVD, copy the entire TS folder, make a new DVD then mount that and then use it in Toast to select individual chapters. What a lot of effort with no design .