Just to be sure I understand the differences between the 2 MC Freezing Ranged Weapon: Frostwalker's Secret has a 6.43% chance of attempting Freeze and gets a bonus in the Frostwalker armor, while Spacefarer's Frost Cannon 38.6% chance of attempting Freeze with a 25% damage penalty as well as a second mode with a 2-turn attack that averages about 1.25 damage multiplier per turn. Is that correct?
The Weapon MC's of Frostgale's Freeze and Mistral's Paralysis are worth 1.125*5% melee, if wielded for an FSB with Frostgale's Legacy and Grace it becomes 1.125*15%.
Spacefarer's Cannon 's Freeze is worth (1.125*30%)/1.01 melee, the /1.01 is an error brought about by an unnecessary undo of Charged shot's *1.01 over time bonus since it only applies to that attack only, it takes a -25% damage penalty.