Is there any way to test product attribute changes in the shopify admin section without making those changes permanently? Like using a duplicate theme? I want to test changing product type of a bunch of products but I don't want it to mess up the collections page of the live site until I can sort out the collections page rules
A duplicate theme would not work since it would still use the same underlying product data.
You can make a draft product and then use the preview to see its changes. Given this maybe you just duplicate the products in question then keep the duplicates in the draft status and view changes using the preview button. Though with this approach the product will not show up on the collections page.