This makes the case > 10L.
Others will also ask for 30mm rad AIO support, for AIOs like NZXT Kraken, so you can add 3mm on top of your proposal, where does it end? There are many sandwich style cases 10-14L that support mainstream 240 AIO + dual 25mm thick fans. Why not one of those, so many to choose from.
Another issue is performance expectations. This layout is a lot more dense or crammed than other layouts, fan with good static pressure really helps. Unfortunately, most AIOs bundle inferior fans compare to the Noctua / Arctic offerings, a lot of 25mm fans are even *worse than Noctua / Arctic slim fans in terms of noise vs performance. By limiting the fans to Noctua / Arctic slim fans on 240 AIO builds, people will likely get better performance vs. noise.
Anyways, making the case >10L sacrifices uniqueness for questionable performance gain seems sacrilegious.
I guess it's also a builder mentality, I like building things, so I prefer to encourage others to build their own full loop (soft tube) over getting an AIO.
