I just made a lead weight and bolted in the spare hole in the tailwheel gear.
Started at 5lbs and ended at 14. I could fly without it but it has a super heavy stick on final approach. I gained 4 mph when I added the weight on the same fuel burn by balancing the plane a little better and landings are much easier for me.
I wanted the earth x battery because of the extra power. I knew I would have to add the weight but it takes much less on the tail then it does in the battery compartment.
Yes your ground adjustable prop is 16 lb lighter and will help your balance a lot.