Maybe a product like this could have been useful: https://www.amazon.co.jp/dp/B0CNVSNX1X (Sorry, it’s a link to Amazon Japan.) You’re using quite a large case with the H9 Flow. I used to have an H7 Flow myself.

Yeah, hard to believe they messed up with the air filters. I was shocked to be honest. But, I just ordered some filter material and cut it into the shape I needed and kind of taped inside. Sadly you can't even put magnets on it... but it sort of works. My other case is NZXT H9 Flow: https://nzxt.com/en-intl/products/h9-flow-2023

Fractal Terra is a very cute case. The A3-mATX is a case inspired by Fractal Design’s North. It comes equipped with dust filters on both the bottom and the front, making it a highly maintainable and well-designed case.

Nice. LIAN Li always made good cases! I have the Fractal Terra case which looks kind of similar, but it lacks any filters so it gets super dusty. I had to mod some filters for it. https://www.fractal-design.com/products/cases/terra/

LIAN LI A3-ｍATX Wood Edition (Black)

Looks nice! which case is this?

光る木。