Great question! I work on Bitkey, so I can provide some clarification. 

The term 'Secure Element' typically refers to chips found in smart cards that pass security certifications such as Common Criteria. They have a variety of security features such as tamper resistance, secure key storage, etc. 

Our processor isn't a Secure Element in that sense, but it has a very similar set of security features. Happy to discuss further if you have any questions! 

 Multiple Bitkeys as part of a larger k/N multisig quorum isn't directly supported -- only the default 2/3 multisig split across (app, server, hardware).  

 Ah, so do you mean like having separate bitkeys to support different wallets, but on the same phone and iCloud account? That wouldn't work if using the same iCloud account