laborator 1200

Are these middle plates necessary to the function of the Durst Laborator 1200? I have two models of Durst L1200, one has the middle plates and the other recently bought, does not Does this affect anything with the enlarger?

Hello everyone. I am posting here because I am selling all equipment from my girl friends dark room. Besides the DURST Laborator 1200 and Multigraph there is sinks drying racks and more. The dark room was built by her parents for her for 50k and she only used it a few times before she decided...