You'll have to be more specific as to why you think it's not working? We've tested a few Braton builds, and critical damage always goes up (a lot) with Prelude of Might. The only thing of note we found is that it takes a few seconds to regain the multiplier if you're using Argon Scope to dynamically change your Critical Chance during the mission? But it seems unlikely that you'd be trying to use these together