How to recover with private/public keys and password, but without provisioned device?

I have uninstalled Keybase from all my devices in the past. I have, however, always kept note of my username, passphrase, private key and public key. I expected this would constitute all information necessary to login to Keybase. Alas.

When I log in, the only option I get is to use one of my two "provisioned" devices. These have been uninstalled/replaced. Is there a way I can login with the keys instead? (I would think paper key, but I can't find that option.)

Start by reviewing the issue's recovery scenario: a user has a username, passphrase, private key, and public key but no provisioned device. Determine whether the requested key-based login or paper-key path is supported. Done should mean that the recovery behavior or its documented limitation is clearly established.

Written by the indexing model from the issue text.