I tried mine on courgette (= zucchini?) but they didn't like it at all, and actually seemed scared of it.:-( (...and they never forage or go near the bottom of the cage seemingly a bit afraid of that too!?) But I think working at presenting their veg in a different way each time, whilst allowing for time for them to get used to it / to try it is a good way to find out what they like, and how they like it.
So, good luck, audit, I'm sure you'll find your own way with the foods, and enjoy doing so, just as we all do. It's an interesting journey, I find, and one which serves to get to know your budgie buddies so much better.