OP, I had the same reaction as Don S. I couldn't tell what you meant by "indexing my Basic Strategy" given you said you hadn't even started to count. Not sure what you are doing with Sweet 16 indexes if you haven't started to count and haven't mastered Basic Strategy. I hope you are not learning Basic Strategy only for the player/dealer combinations of the Sweet 16. You have to learn BS for all Player total, Dealer up card combinations before learning anything else. The indexes are the True Counts (you might have a misunderstanding of what that is too) at which you deviate from Basic Strategy. Learn Basic Strategy until you can do it in your sleep, and then start learning to count. Assuming you pick Hi-Lo or other balanced count, master the Running Count. Then learn deck estimation and how to convert the Running Count to a True Count. Then learn how to vary your bet based on the True Count, and then learn the indices and how to deviate from Bsic Strategy when the True Count reaches the index.

Basic Strategy for insurance is "never take insurance". You only can get an advantage taking insurance when the TC >=3, so people say, if you're not counting, don't take insurance. I can see how you may have interpreted this to mean the gain is minimal. In fact it's a bad bet if you're not counting, but if you are counting, there is much to be gained by making the bet above the right True Count.