I understand that . My example starts with a REAL mac product with the legit macOS copy . I then suggest external modifications such as GPU via thunderbolt , Display , whatever really that are not Apple products but still work with the products and Apple gives the OK for users that choose to do so far as I know ? I also ask about changing the GPU to another model you ' d find in a more expensive Mac product , or the the kind that have those various customization options . What difference is there from buying the Mac with a different GPU model vs purchasing that same GPU model and replacing the one you bought beyond warrantysupport ? Even if you replace it with an exact model replacement because for whatever reason it broke . Both cases I ' d still say are Apple hardwareallowed ?