When I have forge of ancients up and feel the urge to build 50 magic items a turn, I store my spare magic items on some researchers or hiding scouts. Sort of an extended lab.
Some games I wish I had a tardis to hold my magic items in...
Perhaps a new magic item that can store 10 other magic items in it and only take up 1 space in your lab. Wardrobe of Clutter or Spare Room of Disorder?