I know the difference between the two, but i'll just say it - while both can cause issues, one is really another level. i refuse to eat jerusalem artichokes (sunchokes) for this reason.
it's too bad that erythritol, for several reasons, fares so poorly in frozen desserts in quantity because i find it the best tolerated in terms of something that is bulking. it's just not that useful in cold stuff or baking anything with a lower water content.
"banned ingredients" in this case, imo, are only a pain insomuch as acquiring them can be expensive, really, we're not talking about anything with health risks. selling is a different story, i guess, but even then, i don't think polydextrose is banned in the EU as a food additive, unless this was done, like, extremely recently:
also, i'd keep an eye out for allulose. it's not banned, either, rather it hasn't yet been allowed. multiple companies are pushing for approval as we speak
too bad that really the sorbet is the issue, here, since it's a lot easier with something like an ice cream full of fat.