The idea is to allow a player to pick all their advantages first then roll for the disadvantages. By doing this you can make sure that none of the desired advantages will be selected as a disadvantage. I hope that makes sense!
Defeats the inherent risk in the system. It'd be too easy to make sure the disadvantages you land are just things that will never matter for your character. Introducing a change like this would also require everyone be given a free mulligan to offset the fact that they weren't picking with this safety in place.