Any chance of making smaller cases than the UGCs? Space is such an issue and I hate to tie up the space of a UGC for Atari, INTV, Genesis, etc.
http://www.videogameboxprotectors.com/ has some small clear plastic boxes for NES and SNES Carts.
Unfortunately, that's the only two types they make for Cart Only, the others they have are for boxed games.
You might want to ask him if he has any plans to make Cart Only Boxes for other systems.
The costs of Tooling, for cutting shapes out of the thin plastic that he uses to make boxes, is far lower than the costs of Injection Molds,
so the odds might be good for him to expand his product lineup into those areas, if he gets enough requests.
For the short term, you may be able to find some Ziplock-Style bags (Relock Bags) that are just big enough to put a game cart into, from an online store.
I currently have no plans to make Game Cases without Manual Support.
Your post reminds me of something I forgot to mention, though...
I made a statement, last year, that my Game Cases wouldn't support the Dust Covers for American NES or SNES Games.

However, that may change.
NESI think it can be accomplished by simply increasing the Cart Area a bit in the NES/SGB Case, and having two sets of locking tabs.
One set of locking tabs would need to be removed so a Sleeved NES Game can fit.
I'll make sure you all can get at them easily with cutting tools (like that weird nail-clipper thing that pops up on these forums from time to time).
You'd just have to cut the top off of them, where the bubble thing extends outward, towards the NES Cart.The second set of locking tabs would be a bit taller, and further apart, to hold the sleeved NES game in place.
The second set could just be ignored by people who don't have sleeved NES Games, or are using the case with an American Super Gameboy.
SNESI'll need to remove part of the side walls in the SNES/SFC Case, to account for the added width near the bottom of the cart,
and make a depression in the case, to account for the added thickness of the dust cover.
My current setup for the SNES Cart Locking Tabs don't come into contact with the area that the dust cover occupies, so they won't need to be removed or repositioned.
I may need to increase the thickness of the case, that is directly under the SNES/SFC Cart Area, so the depression for the Dust cover doesn't wind up being a large rectangular hole in the case.
This is one of those things that need to be worked out with the Prototypers.