LOL, they have minimal crew, have cut science, and it is yet to be seen whether they even get ISS built...
But here you are worried about bring back experiments that may never be done, by astronauts that may never be on the station, on a station that may never be completed.
And just how big are these racks? It will be stupdendously stupid if the racks are of such size and so unpartionable as to only be returned by the shuttle. I remember when they were attempting to justify the ISS based on how quickly these racks would get up there and how much science would get done. Another failed promise on a failed program.