3.0 will work with 2.0 but at 2.0 specs

That adapter will work fine. That same brand is what I use on both of my Mi Box's and I have zero issues with it. Been running solid for months without needing to reboot.

I've tried several USB 2.0 adapters and all of them I tried had issues staying connected after sleep mode. I would need to hard reboot the device to get it back up and going again.

Once you get past a certain point, speed becomes a non-issue. That certain point is streaming a 4k HDR 10bit show. Only need 40-50 MBit/s for that to happen which USB 2.0 can easily do. So when people say wifi for the Mi Box is better because it's faster, they don't really know what they are talking about.

IIRC USB 3.0 is recommended and I can confirm that works

That one will work fine. I got one for my Mi box and no issues at all.

I got my MiBox 3 4K yesterday and the WiFi hits around 35Mb/s on my UniFi AP AC Pro and 70Mb/s BT infinity using the built in speed test on the Netflix app.

My point is, the WiFi doesn't seem too hot either, this was sitting about 6 feet from the AP.

I have a couple of USB3 adapters so I can try them and let you know what if any diff I get. As mentioned the port is USB 2 so I expect the WiFi to be better.

That's the one I use with my mibox, no complaints with it. Decided to use it because the wifi was a bit sketchy at times and for some reason would cause my router to randomly drop 5ghz...but once I switched the mibox to ethernet, wifi issues just disappeared.

All that said, let others are telling you, you'll only get usb 2 speeds even out of a USB 3 adapter because the mibox isn't usb 3. Imo that's fine since USB 2 adapters usually don't even offer gigabit speed and if you even need to use this adapter elsewhere you're not handicapping yourself because you bought a USB 2 adapter