DC38,
I hear you. Don't hesitate, if a ball is not reacting correctly for you, after a few uses, to modify the cover's finish in small stages. It can't hurt, but it sure could help. Good luck.
Regarding the HRG, if people are getting good results with normal drills, (and you and I did not), their release/delivery could be a very rolly one. Older strokers and few younger ones do have that sort of release. There are soooooo many variables involved in a ball's reaction.
--------------------
"None are so blind as those who will not see."