There appears to be no way to Save Multis in JABB. I tried using Logic's own Save preset but the saved preset wouldn't recall. It seems that the only way to do this is to spend more money on Kontakt.
Without wishing to jump to conclusions, not including facilities like 'Sample Start' in a scaled down version of a sampler to encourage buyers to upgrade, I can understand...
...but not including a basic 'Save Multi' is taking it a bit far. After all, any bog standard Akai sample CD, loaded into EXS24 will offer a wealth of features (including Sample Start) and usually cost less than this current crop of 'dedicated instrument' sample sets.
At least build the damn thing with a 'Save' button, please!