The original patch was tested on the same setup: http://mailman.nginx.org/pipermail/nginx-devel/2014-October/006151.html
Do you insist that it does not work in the current state?
Yes, the problem is that the automatic initialization only take place for the default engines, which have to be configured through the configuration file. For the engines that are used ad-hoc, the ENGINE_init() have to be called explicitly.
In my opinion it would be better to have nginx working with engines in both scenarios. And is not a problem to call ENGINE_init() from multiple places, since the API takes care of this case.