Optimisations mainly but major version change due to the fundamentals changing. To make less going on at once, data attributes must be added for data-trig-var="true", data-trig-pixels="true" or data-trig-degrees="true" to create the position css variables. This'll disrupt any current usage of previous versions and would need amendments to make things work again. This'll make trig JS much lighter for use when only using animation triggers when on screen or using the body classes. It also improves the usage when using many scroll animations at once.