get Affdots to track your current dot power and decide for yourself.
not influenced by any other procs, I reckon it's not worth refreshing a UVLS proc over a 10 stack WFC proc ( although I wouldn't know since I don't have UVLS yet to test how powerful a 40+ sec 100% crit buffed agony is, since I reckon that's where the UVLS proc is felt mostly for aff)