@al3xicon there's no way of doing it. It's because of the way of the matrix item is designed. One common problem with matrix is you cannot add or remove matrix dimensions example if you have an item shirt - and the dimensions are size-color-sleeve; and let's say you want to add another dimension say fabric material, that won't be possible. In the 2016.2 new features training they mentioned the functionality will be rolled out. Actually in terms of item conversion - there are no options to convert from one item type to another except for Non-Inventory to Inventory items.