My initial thought was too much velocity loss, but you're not shooting long range (heavy bullets) with that twist rate anyway- so I don't see the velocity loss as a big deal.
As was said above, shorter for the same diameter means stiffer, so usually you would expect to see consistent harmonics- though you already have that with moa accuracy.
So here's my only caveat...
If it's shooting minute accuracy- is it with factory ammo, or handloads?
If it's with factory ammo, I'd say that rifle is shooting as good as is reasonably possible to expect. While I'm a fan of shorter barrels sometimes, if that's the case I probably wouldn't mess with it. You know the old adage, "if it ain't broke..."
While I wouldn't expect cutting/re-crowning to degrade accuracy, harmonics are very unpredictable.