The key to a reliable ragjoint mount is shimming the center hole to fit your hub as tightly as possible to perfectly center it. I use strips cut from aluminum and have had no problems of any kind with the stock kit parts. If your sprocket does not fit the hub tightly, it will move no matter how tight you bolt it. Shimming removes any slop and centers everything.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.