I don't know what the state of either is on a Sony 10 IV, but the answer is almost certainly Lineage. It's the more mature project, and it's way more likely to work. And at the risk of getting on a high horse, Lineage's unfortunate but necessary (if you actually want your phone to work) reliance on proprietary blobs is already bad enough; I certainly wouldn't trust my privacy to a project like Sailfish, which I understand to be partially closed source.