The critical part is proving the device created the seed with sufficient entropy, cc has a chipset that provably does this but it was bypassed by a weaker software based random number generator, thru a faulty firmware upgrade that disabled the hardware number generator. Afaik the only way to prove t...

I would only use jade or seed signer.

Don't trust brands. Learn about entropy and true randomness. Make some practice seeds for a testnet wallet. We don't need to worry about the NSA spying on us for making restnwt wallets. It's okay to use Ian Coleman's bip39 tool for testnet. Does it let you generate shitcoin addresses? Yes, but ...

I think multi-vendor, multi-signature is the way to go (e.g. Trezor & Bitkey, or Ledger & Jade) in a 2/3 set up with someone like Unchained as the 3rd party key.