When i create in solidworks an unique weldment profile i dont have problem to upload this unique part to upchain, but when i want to use more than one weldment profile upchain only create one item.
temporaly to create one item per esch solid profile, in the solidworks part make the secuence, tools, features, save as assembly multisolid.
later, i propagate the custom properties of the profiles and create one item per each derivated part.
in a future its possible that upchain recognize all multisolid profiles when the user mark "this is a weldment structure" to get internally information.