Wow! I honestly had no idea that existed until now. There's certainly an uncanny resemblance, but upon closer inspection there do appear to be some (minor) differences:
1. Their case is (obviously) custom and isn't the same one that the M5StickV uses. Their case also appears to be longer, and the front button is in a different location.
2. The specs of the two devices are similar but seem to be very slightly different: the Jade has Bluetooth, the M5StickV does not. Also, their battery is 240mAh, whereas the M5StickV is 200mAh. Maybe this is why their case is longer?
It's easy to 3d print custom case and I even found
Jade cad STL file on github.
There are even cheaper devices like
M5StickC ESP32 for less tha $14 but they are basic model and they don't have camera integrated.
One more DIY wallet with similar concept like yours is
Bowser.
It says "M5 Bitcoin Pocket," so I'm guessing it's a custom M5 product that is obviously extremely similar to the M5StickV with minor differences?
There are obviously small differences in devices and batteries, but I guess in theory your code for Krux wallet could work perfectly fine even on Jade hardware wallet, and it is currently a bit cheaper than M5StickV.