As cake already supports some hardware wallets like ledger for key signing in bitcoin. It would be very useful to support air-gapped solutions like the seedsigner too. (through qr codes)
Offline signing should be a great usecase for users as it maintains high level of security along with a smartphone to scan codes and trusting cake with its privacy at the same time.
The qr code formats used by seedsigner should be standard one and woud be supported by other devices like blockstream jade air-gapped mode (maybe keystone 3 in air-gapped mode).
I expect this too be simpler to implement with bitcoin than incase of monero qr codes.
hopefully this is considered and implemented soon 