if i am understanding this right - you are saying your stack bends over like it does on the old Ninja machine i have
i also have an Airflex Turbo which has not been modified but already has a stack that has no bend - just a hole with a filter at the top
if thats the case, then Cleansmart have gone to the bended stack at a later date - ie on newer machines
you would just have to check the baffling on the lid etc is ok for it - i know the Airflex had reported problems in the earlier days with sucking water through to the motors so i think they modified the lids to stop it. If they have gone to a U bended stack - maybe the lid is different too?