DUNGEONDEVDUDE'S PROFILE

author=Marrend
Not sure how much this helps, but, the default processing for the evasion check seems to be in Game_Battler?

class Game_Battler < Game_BattlerBase
  #--------------------------------------------------------------------------
  # * Calculate Evasion Rate for Skill/Item
  #--------------------------------------------------------------------------
  def item_eva(user, item)
    return eva if item.physical?    # Return evasion if physical attack
    return mev if item.magical?     # Return magic evasion if magic attack
    return 0
  end
  #--------------------------------------------------------------------------
  # * Apply Effect of Skill/Item
  #--------------------------------------------------------------------------
  def item_apply(user, item)
    @result.clear
    @result.used = item_test(user, item)
    @result.missed = (@result.used && rand >= item_hit(user, item))
    @result.evaded = (!@result.missed && rand < item_eva(user, item))
    if @result.hit?
      unless item.damage.none?
        @result.critical = (rand < item_cri(user, item))
        make_damage_value(user, item)
        execute_damage(user)
      end
      item.effects.each {|effect| item_effect_apply(user, item, effect) }
      item_user_effect(user, item)
    end
  end
end

*Edit: Maybe as a test-run, insert a new code-block with something like...

class Game_Battler < Game_BattlerBase
  #--------------------------------------------------------------------------
  # * Apply Effect of Skill/Item
  #--------------------------------------------------------------------------
  def item_apply(user, item)
    @result.clear
    @result.used = item_test(user, item)
    @result.missed = (@result.used && rand >= item_hit(user, item))
    @result.evaded = (!@result.missed && rand < item_eva(user, item))
    if @result.hit?
      unless item.damage.none?
        @result.critical = (rand < item_cri(user, item))
        make_damage_value(user, item)
        execute_damage(user)
      end
      item.effects.each {|effect| item_effect_apply(user, item, effect) }
      item_user_effect(user, item)
    elsif @result.evaded
      user.add_state(44)
    end
  end
end

...this, and observe if the state is applied after a successful evasion? Might not hurt to set a character's (or enemy's) EVA to, like, 90% or 100% for the purposes of testing too.

author=unity
This is an issue I've always had with Yanfly's battle engine in Ace. I'm no coder, so I'd also be really excited if anyone's figured out a way to fix this.

#==============================================================================

# ** Spriteset_Battle

#------------------------------------------------------------------------------

#  This class brings together battle screen sprites. It's used within the

# Scene_Battle class.

#==============================================================================



class Spriteset_Battle

  #--------------------------------------------------------------------------

  # * Create Viewport

  # ALIAS

  # viewport2 was bumpped up to 101 to display over BattleStatus

  #  viewport2 effects screenflashes + actors(actors viewport changed below)

  # viewport3 was bumpped up to 150 to still be above viewport2

  #  think this one is for weather

  #--------------------------------------------------------------------------

  alias qyf_vp_fix create_viewports

  def create_viewports

    qyf_vp_fix

    @viewport2.z = 101 

    @viewport3.z = 150

  end

  #--------------------------------------------------------------------------

  # * Create Actor Sprite

  #    By default, the actor image is not displayed, but for convenience

  #    a dummy sprite is created for treating enemies and allies the same.

  # OVERWRITE

  #  viewport changed to viewport2 from viewport1

  #--------------------------------------------------------------------------

  def create_actors

    @actor_sprites = Array.new(4) { Sprite_Battler.new(@viewport2) }

  end

end