Personally I don't think I'd bother with redundant keys for most sites/services, only for those of the greatest importance. I think for most of us that list is short enough that redundancy is manageable.
Probably true. But my point is that if there was some secure/easy way to clone a key you wouldn’t need to think about redundant keys at all. If you create a clone you get redundancy for all sites in one sweep
(Most likely this will be solved by the mobile os vendors who will sync and backup your private key for you. Using your phones HSM instead of an external device)
(Most likely this will be solved by the mobile os vendors who will sync and backup your private key for you. Using your phones HSM instead of an external device)