Re: The real question of course
is the hardware compatible with Mint?
I can confirm, from personal experience, that you can disable Secure Boot in the Surface Book's UEFI firmware. If you do so, however, you get a great big red padlock banner at the top of the screen every time you boot - as if to warn "OH MY GOD SECURE BOOT IS DISABLED YOU ARE SO RECKLESS". Haven't tried installing an alternative OS yet but I imagine one might have problems with some of the SB's hardware.