How often would one want to make a selection of (n x 5) vs (n x 5) + 1? I can't claim to have done any research on the matter, but I know from personal experience that I am targeting a multiple of five way more often than I am targeting anything in between. This certainly isn't a suggestion made off of a whimsy, but one made after quite some time with the software. I think I would prefer even sets over odd sets if you don't like skipping a digit, going from 2,4,6,8,10,... instead of 1,3,5,7,9,...
Now obviously you can't tailor the software to my personal preference, but I just don't think I am the only one finding myself targeting multiples of five over odd digits. This also seems like a problem that most people wouldn't know they had, one way or another.