In my opinion, it would be even more useful if we could rearrange (and to go even further: hide) magic spells, just like we can do with prayers. (I would like to see the ability to remove (lower level) Prayers from the list.) So you could, for example, move the highest combat spells you (can) use to the top, and the ones you never/rarely use to the bottom of the list. Great quality of life if you ask me.
I don't know if this is available in OSRS. Doubt it. If it is not, then I guess implementing this in Zenyte would stray too far from OSRS.