The change from “increased freeze chance” to “freeze rate multiplier” was simply a renaming of the stat to try to avoid people assuming that it was a flat chance similar to stats like “ignite chance”. There was no change to what the stat actually does, so 560% freeze rate multiplier in 0.7.4 is just as good as 560% increased freeze chance was in 0.7.3.
In addition to this change many sources of freeze rate multiplier have been buffed, so overall freeze chance should be higher than in 0.7.3.
Currently a big issue with freeze is that the chance is based on the enemy’s maximum health and that scales up very sharply later in the game, so even if you’re getting lots of freeze rate multiplier you rarely freeze enemies later on. This is a problem that we’re planning to address with system changes in 0.7.5.