The save is stored as the client sent it in the new ugc_unsplit table, and each model split from it points back to it (ugc.unsplit_id), so the whole build can be looked at or restored later. A save is kept while any model split from it exists: deleting models removes saves no model points to any more, and deleting a character removes its saves.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>