I have had those tubes vary in weight up tp 17 grains within a a dozen.
I have said it before,if you are already tuned,adding any full length weight,be it tubing,powder,cordage,will stiffen the dynamic tune.I have wasted way to much time experimenting with all types.Never again.
Now if you put the tubes in before tuning,and change front end weight to tune,that can work but you cannot predict the final weight.You will be surprised how much up front weight it will take to bring them to tune.
Regardless how flexible your tubing is,it changes weight distribution and your balance point.This happens because all arrows have a balance point forward of center so the tubing adds more weight behind the balance point .This moves your balance toward the rear.
If your arrows are truly well tuned to start,adding the tube, changes the balance point and anytime you change the balance point,either direction,you change the tune.
Don't take my word for it.mark your balance point,then install your tubing or string.Check your balance point and it will have moved back.You have changed the tune.The heavier the full length weight,the more pronounced this phenomenon will be.
I like a little weight myself but I have learned,after years of experimenting with all manner of full length weights,to choose the right shaft that will get me to a ballpark weight that I want and I avoid the tubes etc. Like the plague.
If I were in your shoes,I would hunt with those at 9 grs .Well tuned,they will work great.If you truly want heavier,I would get some heavier shafts that will get you there without the weights.
Good luck with it.