15 rounds/day is the same as constant, huh? I know combat is normally over rapidly, but I'd prefer something that will apply before my turn ccours.
Not strictly the same, no, but close enough for jazz. I wonder what kind of situation you're in where you expect to lose initiative but not to have displacement ignored, though.
Well, virtually any melee brute will likely tie you in Initiative if you're actually worried about your weapon enhancements (you're likely a melee character if you are). It's likely you have a higher Initiative modifier than most melee foes (ranged foes are likely to beat you), but iteritive probability means you lose sometime.
Basically, against martial types (attackers, not casters), you're likely to lose initiative when you don't want to and they're the ones that care about Displacement the most. Casters you will just lose initiative to in all likelyhood, but even some of their good spells require attack rolls (Ray of Stupidity, I'm looking at you). Basically, against most enemies, it will make a difference and a large set of those are ones you will likely lose initiative to.