It's not actually the blood sugar rise that causes stalls, it's the insulin response and those test strips don't test that. In a non-diabetic, if you get an insulin response the worst thing that will happen is that your blood sugar might go a little lower than normal and you'll get hungry, but that excess insulin will tell your body "it's fat storage time" and the weight loss stalls.
The theory behind the bars not affecting your blood sugar is that if you don't have a blood sugar rise, you won't have an insulin response. The problem is that in a normal person, the body does a very good job of keeping blood sugars fairly stable. The only way to tell if you are having an insulin response (and how much is being produced) is to have circulating insulin levels drawn at specific time intervals after you eat something and that's a very expensive test that most doctors would not be willing to order for a non-diabetic patient.
Another issue is that, as I mentioned above, not everyone reacts to the same food the same way.
Instead of using the test strips to see if you can have those treats or not, how about letting the scale or tape measure decide for you? If you can continue to loose weight and/or inches and have the treats...good for you! If not, then maybe those are something to be saved for maintainance or used as an occasional treat.