So... that's fine, then? Telling people "you get an SD card connector and an m.2, you can't use both at the same time" seems perfectly reasonable to me. Have them overlap, done. Now people who want to use a $5 SD card with the slow speeds that come with that can do so, and people who want high speed but with the higher cost of a reliable m.2 drive instead can do so, too. No one loses.