If you prefer that case and there is availability, then feel free to take that one. It's not like we're forcing you to not go for the velka, but there is a reason why you're commenting here 
As for "maximum focus on ventilation" - note that Sliger's console also is vented everywhere and AfaiR the tests made by Level1Techs have shown that performance differences between that case and Sentry 2.0 were negligible.
That console style case from Velka seems like a good way to make something that is cheap (in context of construction and amount of bends per piece) and focused on vertical orientation, but the drawbacks will come when you'll want to put it laying horizontally or transport it.
And also I wouldn't really expect to use the advantages of 3-slot GPU without additional fans in a case, maybe apart from the fact that you can get your hands on that kind of card easier. It's like putting a 1000 horsepower engine in small compact city car because it fits, but it doesn't make much sense outside game realm.
What we're trying to achieve is to make a case that is kind of a reference of what SteamMachine's supposed to be, and just because there is a lot of happening in the industry all the time, doesn't mean we should be jumping around from idea to idea. It's just that so far the price tag made it so that the case was filled in with expensive components, but it shouldn't be like that. It's actually a bad idea to squeeze in a 3090 in a case like this because you will starving the card's cooling system of fresh air that should be delivered constantly by multiple fans in the case. Just because you can, doesn't mean it makes sense.
