Since its generally agreed the distance and spin attributes of balls doesn't matter in putting, consider using a lower cost ball with the same meter attribute. You have the GI2-SD2 equipped. @ 155cr per sleeve. Consider buying a sleeve of GI2-S @ 64cr They have better durability (more hits per ball) as well.
Then use the practice round and the mulligan feature to hit the same putt repeatedly until you learn the break.