“Solved.”
Not.
I was getting the “Option value already exists” error when trying to add “Unframed” as a variant to a product that already had framed options. So trying to figure out what “change it 1 by 1” is supposed to mean, I started over by adding just the Variant and saving. When I did that it gave me the error: “Cannot make changes because at least one product variant is missing a required SKU.” Ooookay. So I entered SKUs for each variant. Then I get “Option value already exists.”
Now I’m stuck in an infinte loop of frustration and wondering why I decided to try Shopify and not stick with Woocommerce.