Apparently, key shells do exist. Here's an amazon listing for one
https://www.amazon.com/beler-Button-.../dp/B07FJ781BH but they are uncut. After some research, original key shells are glued shut and the key blade is molded into the shell so transferring the key blade will be pretty much impossible. What I find interesting is that the BMW emblem on the keys can be separately ordered and that tiny little piece is ~$10 (part number 66122155753).