FWIW, we just check Google Maps while we are driving but usually, it says that I4 is the fastest (or within a few minutes) so we just stay on that (as painful as it can be to cross Orlando on the I4).
E.g. at the moment, from Daytona To FW, the fastest route is I4, taking 417 is 15 minutes longer (we've gone that way to avoid an accident in the past) and 46/429 is 5 minutes more than 417. I suspect that you'll lose so much time on the 46 that it's rarely worth taking that route (but I'm not a local).