Some questions regarding the 4.2 test / release

Hey folks, I’m using 4.1 atm and I was wondering if you can tell how you test 4.2 release while continuing using 4.1 as primary one: you dual boot or what exactly?
Also, due to my hardware, I need to update grub right away after installation to not cause any issues. As I got it, the current 4.2 way to update grub is: grub2-mkconfig -o /boot/grub2/grub.cfg ?
Did the path to grub itself also changed or is it the same?

Yes:

Only config location, if I understand it right.