I bought a monitor since the smarts in my smart-tv died, making the entire display unusable. Now I wanted to use a separate SBC for smarts in the “dumb” monitor. I would have gone for a modded fire-stick, but Amazon in their infinite wisdom, sunset all versions except the 720p potato and the smart-speaker-cube. I’m currently using a RaspberryPi 4 and looking at argon one for a remote control case. Googles widevine does limit the DRM on some content I “own” though. With Amazon on course to EOL the more sane sticks, are there any well-moddable streaming-sticks/boxes, that bring the relevant codecs and DRMs?
I’d say put your RPi4 in a Flirc passive case and use Kodi via LibreElec.
The Argon One connects the fan control in a funky way so your OS must have some way to configure the fan controller. I know Batocera v41 has Kodi 21 built in and their wiki says how to get an ArgonOne working properly. You can then have it set to boot into Kodi and have retro emulation as a secondary option.
From what I’ve seen, the argon does passive-cool alright too. With Flirc I’d need to keep the mini-HDMI-dongle and buy a separate IR dongle, that takes up a usb-slot and doesn’t have a low-power MCU. My Pi is currently in a no-name passive-case already. Unless I misunderstood you, I don’t see the advantage.
It sounds like my case recomendation doesn’t fit your needs. However, the rest of what I said still stands