Chocolate Chip? I need to know the specifics before I can... lend my services.
It depends on the subject btw. In some subjects you'll find that the preliminary content (Year 11 Topics) is not as applicable in Year 12 whereas in other subjects, Year 11 topics do return in the HSC such as Maths or Physics. The new syllabuses aimed to integrate both Year 11 and 12 so that there was some overlap with the content so on average you'd find that knowing your prelim content is necessary to advance onto Year 12. The Year 11 topics, most of the times, aren't directly assessed in the HSC but are sort of assumed knowledge, like you require them to understand the topics in Year 12.