Thanks for explaining your view, that helped me remember my thoughts on this.

My view is you need part of the seed saved on the device and part of it in your brain to avoid physical attacks on the device, so that functionality is more important than a secure element.

Trezor allows that with "13th word" seed setup 

 Passphrase / durress pin is definitely a good feature. But I do think having a device where the seed is not extractable with physical access is a must have.  

 I don't see how that would ever be possible without going all the way to a brainwallet