I don’t want efi for default because not all Distri prefer Uefi. The installer is not able to have option !
Then you would need to change the boot mode in your systems firmware to Legacy (BIOS) mode instead of EFI and boot the live media in that mode. In other words, what ever mode you boot the live media from is the mode it installs in.
This may be very helpful to you: https://wiki.manjaro.org/index.php?title=BIOS_and_UEFI
On my MSI-Board there is configured in the systems firmware boot Legacy/Uefi. Alternative would uefi only. Also the Netrunner installer is not recognize to identify the location. Thats a bug. Netrunner 17 installer isn’t perfect but better.
And it is still not possible to choose where to install Grub from. Standart is MBR and can not be changed, second bug since look my post: “http://forums.netrunner.com/showthread.php?tid=17847” / 8th July 2015, 17:13 (This post was last modified: 8th July 2015, 20:38 by PitTux.).
OK, when booting there should be an option to boot the live media (DVD or USB) in either UEFI or legacy mode, depending on which method you choose to boot the Live media, the installer options will change for that mode.
Calamares is the installer for NR Rolling, If this is trully a bug then please submit a bug report upstream.
https://calamares.io/bugs/secure/Dashboard.jspa