Let it cut. I do it all the time with Photorag, German Etching, William Turner 310 grams.
Keep your head carriage bar oiled, replace the belt when it gets old, put in a new disc knife when you think it is getting blunt but use the machine as it is intended.
Met vriendelijke groet, Ernsthttp://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2012, 500+ inkjet media white spectral plots.