Clockwork does not amplify CP ratios. It amplifies built CP, and there is a difference
The Wrong Way
Clockwork does not amplify CP ratios, but for comparison I'll show what that looks like. 30% of a 400% CP ratio is a new CP ratio of 520%. Meaning a Shatterglass (150 CP) deals base 780 damage. This is wrong because that's not what Clockwork is doing
The Right Way
Clockwork amplifies built CP, meaning that a Shatterglass (150 CP) is supplying you 180 CP. On an ability with a 400% CP ratio, this now equates to 720 base damage
Bonus: Clockwork + Broken Myth:
Clockwork amplifies your base CP (new CP = old CP * 1.3), then your CP ratio and base damage are applied (base damage = ability base damage + CPratio * new CP). Now Broken Myth amplifies your base damage (new base damage = old base damage * 1 + (# BM stacks * 0.07)). Furthermore, your damage is granted pierce, so rather than the normal damage equation (old damage dealt = new base damage / 1 + Armor||Shield/100), you deal with the piercing damage equation: pierced damage dealt = %pierce * new base damage + (1 - %pierce) * old damage dealt