You are correct, maltodextrin is bad news, and it's almost impossible to find sf jello powder without it. I bought some food flavorings on Amazon and I make my jello using plain gelatin with Cascade Ice fruit flavored carbonated drink instead of water, stevia, and a little food flavoring.
CM won't let me add a link, but if you search Amazon for the following you will find the products I bought:
Tasty Living Variety of LorAnn Oils Food Flavoring - 12 Fruit Flavors
I eat the store bought containers Sugar Free jello 2 pack, it does not list maltodextrin, which by the way has been approved as a food additive by FDA. I've had this as a dessert w/ extra creamy cool whip and raspberries for the past 12 months. Beware it maltodextrin can spike blood glucose levels if eaten in large quantities. But do not see this ingredient listed in the refrigerated jello section at grocers.