The High point balancer requires a smooth shaft to run on the wheels.
The threads of the bolt will mess you up big time.
You said that you are using a table to get the blades straight, that means that both trailing edges are in the same direction and could give you the weight bias mentioned above.
If there is a 2 gram difference in weight and the CGs are the same you should see a big imbalance on any balancer.
If the weights and CGs are the same, They should show as balanced on any balancer.
I found that even a cheap plastic balancer made fore heli blades worked better than my High Point.
When I was using a High point for blades, the only way I could get consistent, repeatable results was to make up a dummy head and main shaft to mount the blades to.
It had the grips locked at 0 pitch.
I balanced the head separately with no blades.
I won't go into how I got the blades straight cuz I was young and immortal at the time.
RAMS Club President