I was being (mostly) facetious about the intonation. Come to think of it, ukulele string spacing is often wider at the saddle than at the nut, causing the strings to be slightly longer than scale length, so the percent increase in string length would be even lower. It would still affect intonation differently for each fret. I'm pretty sure fret locations nearest the nut, where string tension is higher, would be more affected. No idea how meaningful the impact on intonation would be.
Even if the intonation implications are negligible, offsetting the nut slot could lead to a host of other issues. The most significant one I can think of is the potential for string conflict between the A and E strings. On my Kala tenor, a 2 mm offset at the nut would bring the A string 25% closer to the E string. You might find you quit muting the A string with the index finger only to begin muting the A or E strings by accident when trying to fret one string or the other. Again, this would be most noticeable at the nut, but the problem would continue to the saddle. A 2 mm offset at the nut is a 1 mm offset at the 12th fret. Even on my Kanile'a with its generous string spacing, this equates to about a 9% reduction in space between the A and E strings at the 12th fret and a 8.5% reduction where the neck joins the body. Spacing the strings out more at the saddle creates a margin for error when fingerpicking, and a 8.5% reduction is a big chunk taken out of that margin. On ukuleles with closer string spacing, the impact of this will be greater. If you fingerpick, the impact of this might be as great as the impact on the fretting hand near the nut.
Most of the gains you want from offsetting the string at the nut would be had by the left hand when it is near the nut; the string would still approach the edge of the fretboard as your hand approached the body because the strings spread out towards the saddle. However, the potential for problems caused by the offset string is also greater for the left hand at the nut; placing the A and E strings closer together might create issues when trying to fret one string but not the other. Additionally, this change might create issues for the right hand.
I haven't even started on what effect this might have on the "mind" of the thumb when trying to rock melody between the outside strings, but I've gone on long enough.
It's your uke; feel free to experiment. The worst is that you'll be out labor and a nut. If you do experiment with reslotting the nut to offset the string, let us know how it turns out.