This offline transaction signing feature was PR'ed to master in early October. I generally know how this is supposed to work, as many others no doubt do as well. But what are the details?
On the internet-facing computer:
Can I have a regular hot wallet, in addition to a cold view-only wallet that requires transactions to be signed by the air-gapped computer? (I would think cold wallet would be separate with its own mnemonic seed.)
Is there something about the wallet that requires cold transaction-signing that is different than a typical view-only wallet?
How does the view-only version of the wallet get set up, so that it knows there is an air-gapped computer required for signing? (Maybe it doesn't "need to know." Maybe it's just a matter of having the ability to create an unsigned transaction, and then broadcast a signed transaction?)
On the air-gapped (not internet-facing) computer:
How recent does the version of the blockchain need to be in order to sign transactions? Will it always be able to sign transactions that spend deposits occurring at or the latest block on its copy of the blockchain?
When a more recent copy of the blockchain is pasted/moved to the air-gapped computer, what is the rescan/refresh procedure? That is, for example, will I need to recall the latest block from the prior copy, in order to scan only the applicable new blocks? Or perhaps this is automated somehow?