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.