I want to upload my tables piecemeal - one table, refine model, upload the next table, refine model. the data importer won't let me do this, and even goes horribly wrong. if i upload my organizations, i can create my model with one relationship. i then upload my positions. now i can't a) reference the model i just created to map relationships to organizations or b) the model isn't even there anymore in the UI (although based on my queries, the graph is still intact.) i'm totally confused