It's been around for quite a while actually (it was in Camel 2), but it's not really useful the vast majority of the time, since it is called just prior to execution but after compilation, so that it can't affect that. Choosing a BEGIN block of an INIT block is rarely wrong - the opposite case would quite frequently be.

I guess it's one of those things that you almost never need, but are very useful in that one out of 100,000 cases where you do.

Makeshifts last the longest.