I'm repurposing an HP T620 as a "chromebook", "chromebox"... whatever. The thinclient was upgraded to 8Gb RAM, but still retains the 16Gb M2 SATA hard disk.

I've installed the official ChromeOS Flex, and it works fine (the HP T620 is on the list of certified things). The problem is that my HP T620 lacks an internal wifi card, and it seems that there is no list of USB wifi adapters that work. I've tried three of them on my box, with mixed results.
- An unbranded chinese adapter: Based on Realtek 8176 chipset, with a very big antenna. It doesn't work. Looking into dmesg, there is a message that says that the driver is a "staging" one... maybe it's not fully loading?
- A "nano" adapter: Based on Realtek 8192 chipset. It works, but being a "nano" thing (it only sticks out about 3 or 4 mm) the antenna is not good and the connection is unstable (unless you're very near to the AP).
- A TP-Link TL-722 (newer variant): Also based on Realtek 8192, with big antenna... but for some strange reason refuses to work. TP-Link changed the USB IDs to reflect their brand, so maybe they did other changes that prevent it from working (the adapter works fine on Windows laptops).

So I'm looking to buy a new USB adapter, with a good antenna so it works everywhere on my house and that is fully compatible with Chrome OS Flex... any idea?