I'd love to help/see NIP26 adoption with hardware wallets or other secure key stores. Ensuring there is less need to transmit or otherwise handle long-lived irrevocable credentials is crucial.  

 What are the problems with it? Is it mostly solved by 46, or something else? 

I'm primarily concerned about that if identity is tied to a particular key pair, and that private key cannot be revoked or at least failed to renew without the public key changing, a bad client can permanently irrevocably compromise your "account."