Have you found any information on why they're not dishwasher safe? My impression is that it would be because of the heat (heating element) at the bottom of a traditional dishwasher - and for the same reasons why other plastic products claim only "top rack safe."

My recommendation in that case is to get a Fisher and Paykel DishDrawer (or one of the private-labeled products from Kitchenaid or Kenmore). You can put top-rack-only items anywhere in it. There are no exposed heating elements inside the washing compartment and the drying portion of the cycle uses only a fan to blow air around, not a method comparable to the bake setting on an oven.