I’m careful of inulin (almost always from chicory) as an additive in “low net carb” foods, because it does raise my BG in almost exactly the same way that a starch would. I use Kirkland brand protein bars, which have 19g of carbs (not including Erythritol, which is completely neutral in terms of BG for me and has virtually no calories). 15g of those carbs are from inulin (chicory root source, I believe).
It took me a while to realize that the “4 net carbs” were not affecting me like 4g of carbs. The bars were affecting me like 19g of carbs would. So I still eat them (high in protein, and I often need a bit of BG raising carbs immediately after I workout), but I now treat them as 19g of carbs.
So, inulin hasn’t been some sort of magical fiber that regulates my BG. The only one of those I know of from personal experience is unmodified potato starch (which actually functions as insoluble fiber).