Snowdrift & Ice Thorns

Snowdrift seems didn’t work properly on “2% cold penatration with frostbite per 10% FRM”
I stack FRM for 463% but it only shows 29% frostbite chances, shouldn’t it be 2% *46 = 92%?
And then, Ice Thorns SPEC don’t need the “Protector’s Briar” to cast on allies.
I can directly cast on my minions, same icon with “Storm Aid”, is “allies” here means other party players?

Cold penetration is not chance to apply frostbite
The boots give you some chance to frostbite on hit.
And with your frm you have 92% cold resist penetration