Oh, it's possible...it's just a pain in the behind and a task I try my best to avoid!
I tried to group them by type, i.e., all the little yellow ones together, all the Ogham together, all the musical instruments together, etc.--which tends to break down when Kernos adds new things when I'm not looking
-- but rearranging them takes so long that it isn't something I want start in on unless I have a few hours to devote to it!
I'll keep it in mind, though--no doubt one day I'll gird my loins and tackle the job. But I hoped my suggestion of typed codes might provide a temporary solution!