Comment # 5 on bug 902628 from Jiri Srain

The problem here, which I see, is that the options are not mutually exclusive.
It can make sense to keep the additional copy in boot sector - in case MBR gets
accidentally rewritten by other operating system, for example.

Also, when enabling MBR, accidentally keeping BL also in root partition does
not cause any harm (otherwise, it would).

Instead of changing the logic, I would rather think about a redesign of the
solution - instead of having the links change settings instantaly, they could
show a pop-up with a selection of possible targets. Anyway, this is for
discussion with usability experts.