Maugust789 The extensions add enough weight to still alter the swingweight, but you should at least see how you like it. With the extensions and standard grips, it should be noticeable.
If you are only extending 1/2", you don't have to use the whole length of the insert portion. There are no rules, but for me, weak swinger, I only need as much inside the shaft as there is going to be outside the shaft. If you are stronger, you should still be plenty safe with only 1" overlap inside the shaft. Otherwise you are adding a bunch of steel up there.