Please note that Kruh wallet can't function as normal hardware wallet, but more like a cosigner in a multisignature setup, and every time you turn it off from power you will wipe his memory, and you will have to import your key every time you turn it on.
Other thing that I don't like is the fact that code is new, not time tested and there could be some hidden bugs even in this simple code.
This wallet has good and bad sides, it's very cheap and I think it serves great purpose for multisig device.

Here are some images and videos how Krux works in real life:
https://twitter.com/DIYbitcoin/status/1437293312810143745