Probably obvious to you more experienced round bale folks but I have found that running the baler at a bit lower rpm seems to be a lot gentler on the bale than running at or near full pto rpm. I am trying to run it just fast enough so the pickup is running slightly above forward speed.

Wrapping a lot of wet hay the past few years, baler rpm didn't make a lot of difference.  With this dry spell and try to make dry bales, the pto rpm has a much greater effect on the alfalfa leaves left on the hitch.