Use the Unifying receiver, that's what I've been doing for 10 years with multiple devices. It costs like 15 bucks, it's tiny and works flawlessly for any OS/device combo I throw at it, including the Ubuntu 16 + MX Master 2S + K800 that I'm using right now. There's an app called [Solaar](https://github.com/pwr-Solaar/Solaar) that helps with the pairing and such but I don't think it's strictly necessary (can't remember the last time I ran it).
Yes I can imagine it to be annoying for some use cases. My Carbon has, among others, 2 USB-A ports, 2 USB-C ports plus a trackpoint and a pretty good trackpad. My older Thinkpads have more USB-A ports than I'll ever need. So the unifying receivers are only used when sitting at a desk, where they're permanently plugged to USB-C hubs.
