They support seedsigner?
I have created my first Unchained vault!
Two nostr:npub17tyke9lkgxd98ruyeul6wt3pj3s9uxzgp9hxu5tsenjmweue6sqq4y3mgl keys, plus Unchained's collaborate custody key.
First minor hiccup: for some reason they skip the first receive addr so for a moment I thought my parallel wallet in Sparrow was somehow wrong.
Discussion
NOPE!! But they use completely standard multisig descriptors and psbts so, when used in combination with other tools that DO support SeedSigner (e.g. Sparrow), you find a way to do anything you need to do.
File it under: Proven possible, but not nearly as straightforward as a direct integration would be, and don't expect their customer support to be able to help you if you're going to opt to venture outside their necessarily more limited, more guardrailed system.