Note I edited my post to say that 4.19 appears to fix it, however in 4.17 a bug was introduced that regularly crashes the editor if you compile a BP character that is based on a c++ class and has another BP character as its child.
4.17-18 introduced the character movement re-write, gesturing system, the fully built in seated / car system, the movement action system, and a bunch of helper nodes to the plugin. 4.16 would be missing out on a lot plugin wise.