After looking into this, nostr:nprofile1qqszxn5k652cqq9afs8eccyf6rwl0rpx0z5fymr5amu25t05w4pajespz4mhxue69uhhyetvv9ujumt0wd68ytnsw43qzxnhwden5te0wfjkccte9enk2arpd338jtnrdakj7a33qy8hwumn8ghj7mn0wd68ytnddaksxczka7 is correct. It appears CLI and nostr:nprofile1qqsrf5h4ya83jk8u6t9jgc76h6kalz3plp9vusjpm2ygqgalqhxgp9gpzfmhxue69uhk7enxvd5xz6tw9ec82cspp4mhxue69uhkummn9ekx7mqpzpmhxue69uhkummnw3ezumrpdejqd2970s are the only methods to setup an address when closing a channel.

It reads that it has to be part of the close request. That means you have to be the one closing to channel to set this alternative address. It doesn't appear you get the opportunity if the other party closes.

It would be cool if an alternative address (cold storage) could be part of the message when opening a channel with a peer.

nostr:nevent1qqsgq4umajfdjvqsy472latlflv6yjae7dw2sdl443hp6se72fumaesppemhxue69uhkummn9ekx7mp0qgspyhpe6yflj5dl40e3nmd73sxcxjj0ul06pkxr6s3385teqreu33crqsqqqqqpues0d0