Can I not use Amber? Not sure how to log in 
This is what my Nostr contact list with over 2600 pubkeys looks like, and an example of why you should consider reducing your follow count. This 190kb file has to be updated and saved to my relays every time I follow or unfollow someone.
It’s why I built nostr:npub1pvz2c9z4pau26xdwfya24d0qhn6ne8zp9vwjuyxw629wkj9vh5lsrrsd4h and why I’m building more tools to help reduce my (and your) bandwidth footprint.
Discussion
That's right. NIP-46 signers don't work with this app.
I explained why here:
nostr:note1v2fdytj44trsnvt7yqal83r7c0mxfl4y5qqdrvp9uqaj9tpyf3ysd7n0gf
Good idea! I haven’t even tried this myself but I’ve been told it works well.