Just superglue a ball bearing in there as another option.
Acetone will dissolve it in the workstand at home (make sure it's the 100% stuff), though will take about 20 mins with some fettling to get the ball bearing out. No thief gonna wait that long.
Good thing about bullmoose bars is I can put a lock through it. I also use hexlox on the pinch bolt. Might even glue a bearing into the top cap…