I'd love to see the Chef's Table round revamped with the contestants working alongside a professional chef to take one of one of their more rustic earlier round dishes and refining/enhancing it to become close to a 'Michelin Star Level' dish. I'd be far more interested in watching the development process, seeing the transition from home kitchen to professional kitchen, and then serving one of their own concepts to the top chefs than watching them just replicating someone else's food.
I've said it before but I wish that by finals week they'd all had to demonstrate certain cuisines/skills. You can't win Strictly by only dancing a waltz but some MC contestants go a long way on a fairly limited range of dishes or without ever doing, for example, a fish dish, pastry, or a dessert. Maybe include a version of the 'Skills Test' that they use on the professionals? And have a round where they have to actually know the cost of their dishes (a vital skill for a professional chef) - rather than wheeling out the langoustines, lobster, steak etc.
The mass catering rounds are good - I'll keep those!