This.
This talent makes no sense. It is behind a cleave/aoe talent in which situation you barely cast any frostbolt.
For singletarget 1% per cast is too litle. You won’t cast 15 frotsbolts during an entire duration of the icy veins because you have flurry lances to cast. If you do you will have like 5 seconds left to enjoy the 15% spellpower. Also does not worth the 2 points for singletarget build.
For aoe if frostbolt hits 3 targets you get 3% but again you have too much going on. You have to orb lance spam blizzard spam reset orb orb again lances. You almost won’t cast frostbolt at all.
It should be relocated on the tree and changed the 1% to like 2-3% per cast.