The Bubble Club chair by Starck is a great example of rotomoulding - it’s comfortable too because it’s hollow. Smallest radii I’ve seen were about 3mm and you can incorporate several technical features. The disadvantage is that the PE material scratches quickly, unless a new material has been developed that works with rotomolding that remains a disadvantage.
On that note, I am developing several bottles and am looking for examples that show the limits of the technique in terms of small deep sections, undercuts, patterns etc.