Will sugar alcohols thicken a sorbet?
Well, I got around to braving this and potentially sacrificing a box of strawberries at ‘rona prices, and going half xylitol half syrup at ~25% added sugars of total it turned out… fine. Not as creamy as using all syrup but not sandy the way my early all sugar batches did - at a guess, it behaved barely different from table sugar for me. 1 part substitute : 2 parts syrup might be better, but at that point it seems like mostly a pointless complication and expense - xylitol has 60% the calories of sugar, cutting the calories of the sorbet by all of 13%.