While you are on point in some ways, it is misguided to use traditional freestyle ski events as a guideline for what to expect when and if ski halfpipe gets in. It is halfpipe, it will be much more in line with snowboard halfpipe, than it will be with aerials or moguls (even though Joe F and the FIS fresstyle ski crew will be involved). There are already talks happening at FIS level to have ski and snowboard halfpipe working together.
And in Canada, the Olympic and Nationally sanctioned halfpipe snowboarders do not have to certify their inverts or doubles on water ramps. Expect to see ski halfpipe working more closely with snowboard halfpipe in the future at an NSA level in Canada.