The golf balls are from over agitation. Try experimenting with stand development. Process the HP5+ in a 1:100 solution at 20C. At this dilution you're going to want about a liter of solution to make sure you've got enough Rodinal in there. Ever so gently swirl for 20-30s. Then just let it sit for 30 minutes. Then more very gentle swirls for about 5 seconds. Then leave it alone for another half an hour.
Try that as a starting point with a test roll, let us know if it's not remarkably better.
I'm sorry but this is not good advice. Stand development is just not good. And the grain will still be pronounced. I'm not even sure there is a connection between shaking and grain size.