Nope, and not sure I would. Caramelization is the primary reason for sugar in a rub, not flavor (imo). Plenty of seasonings to give great flavor, but you'll get "great" bark with sugar. If you can't have sugar, I'd give the artificial stuff a try, and let us know how it works!
I can't have sugar, but I know that erythritol carmelizes, because that is what I use on creme brulee. Also some of the inulin based sweeteners will carmelize, although I'd be a little careful with those because some people (but not all) have <ahem> digestive issues with inulin. My go-to sweetener is a product called Swerve. I haven't tried it yet in a rub, but when I do I'll let you kjnow how it turns out.
large amounts of stevia are used in certain countries as a contraceptive. If your an old man like me with 3 kids already, I guess its fine. If your a young lad or lass, I would use other sweeteners.