Thank you for finding that-- it always helps to have unfamiliar packaging concepts explained in pictures, and that's why I wanted to see what was being spoken of on that Schitt's Creek all-in-one.
And if you get VEI's 20-disc Cannon all-in-one, you'll have 6-7 outings per disc, which might bring the quality down even further (let alone that the discs initially come in a disc wallet; I had to modify that and put them in 20 white paper CD envelopes, one per disc).
Certainly agreed-- wanted to see what you were talking about by saying "15 discs in a 10 disc case," so I researched the Schitt's Creek all-in-one on EBay, but none of the entries show pictures of that (they all show the front, back and outside, or worse, have just one picture).
And one major example of that is the original version of the M Squad all-in-one (15 discs and a music CD on its 8 panels). It's so expansive that I can only take a shot of part of it, but here's what it looks like within.
This is probably how I should have gotten The Streets of San Francisco-- much as I love that ABC police procedural of the 70s (and believe it to be one of the best I've ever seen), working with that all-in-one that I have now is quite the adventure.