Just out of curiosity, I measured my KoAloha L/N Concert & my Ohana L/N Soprano, with a rule.
(Edit: These are the depths without the fretboard.)
Nut depth, K=12, O=13, & at the 7th fret, (measured here because the heel on the Ohana gets in the way at the 12th), K=14. O=15.
These are, of course not perfectly accurate owing to using a rule & not a micrometer, but shows that they are as close as it won't make a difference.
@ UkingViking
The KoAloha L/N Concert is a nice uke, & I can see that you are missing a L/N Concert.
(....& you don't seem to have a baritone either....
)