Hang in there.........there's a good chance that SOMEWHERE out there is a Chop Cup Baseball with the right "innards" to work great with your particular "strength" of Chop Cup.
If not, don't despair, because there are some magicians here on The Magic Café whom, I believe, can help you or at least help steer you in the right directions.....You May want to consider looking them up and PM'ing Them....one is Frank Starsinic who owns THE AMBITIOUS Card.....they have GREAT STUFF For Cups'n'Balls and Chop Cup workers, as does Donnie Buckley (sp?) who Owns Rings 'n' Things II, and who stocks (or at least did stock) adjustable-strength Chop Cup Balls, although I'm not so sure that they would be available as chopped, adjustable baseballs.
Having said that, personally, to me at least" it's the "feel and/or force of the DISCHARGE of the chop ball" that's critical to your movements and timing in your routine, so, IF the load baseballs for any reason, don't cut and run YET, that is if your're absolutely SET on using baseballs, and that could be "PLAN B", which is a non-gimmicked cup using our old friend, the Magnetic Ring that You're wearing....
I'm confidant that you'll figure it out.