The only problem is that Flex ATX PSUs are really loud.
They can be, but that's by no means set in stone. As I said, the front 92mm case fan in this design provides the PSU with an abundance of fresh air directly. If the PSU has a temperature-controlled fan, there should be much less need for it to spin up.
I could see a system builder like Maingear, Origin, Falcon Northwest, or the like being interested. But the very limited component choice compared to the A4-SFX seems like it'd be a problem from a marketing perspective.
I know there are some people who really like their dust filtering, but I doubt very many like it that much.
I haven't seen any 92 mm AIO liquid coolers.
There aren't that many 92 mm fans to choose from compared to 120 mm models.
The restrictions the design imposes seem even more tight in reality, because the reference blower card should also not be too short, or the fan will sit behind the motherboard. Considering there is only one or two 92mm AIO sets with limited global availability that I know of, the compatibility might be too strict. Three possible market trends might make this case not be able to have any future upgrades or replacement parts: shorter OEM cards, Asetek dropping the 92mm AIO, no (good) FlexATX PSU offerings.
As
@Aibohphobia said:
Asetek sells the only 92mm AIO that I know of, but has done so for years (through their ebay store). To be clear, if we were to go ahead with this project as a product, we would likely have to sell it as a semi-barebones and include the PSU and possibly AIO. So the future availability of those parts isn't likely to be an issue in this case.
In regards to reference blowers getting shorter or going away, I don't see that happening, honestly. They've been more or less standard for how many years now? At best, we might see them get a half inch to an inch shorter, but then again there's really not much value in that. In a blower cooler you can only really reduce the size of the heatsink, and that's only going to hurt thermals and noise.
As is, this concept is only slightly larger than the Razer Core, but otherwise has very similar dimensions. In principle, it should provide reasonably good CPU and system cooling - better than nearly any other case at this size. It seems to me at least, that for a certain segment of the market who need a very compact, full-performance system, it could be a very compelling proposition.