PS: what may happen someday is a merge of OXCE and OXCE+ ... but it's a bit early to talk about that
Everyone got his answers and everybody is right. There is only different point of views.
Merging xce and xce+ is a very good idea. Yankes and you are dedicated and talented artists who got nearly same goals about giving more options to this game. I can clearly see that. With you, this game became one of best tactical and strategical game ever done.
So for this reason, as a new moder who wants to create something good with all options under my hand, I don't see a reason to have xce and xce+ plus separately. Xce should be a project done by all the coders who knows what they do, how to test it and how to make it bug free.
You are inside this for years and probably get use to it how to work like this as a developer and moder same time. But it's really mass for new comers with no reason.
If you ask me, there should be only nightly and xce+. Nightly for default openxcom devs and moders with key features which xce got time to time, and Xce+ should have all the everything and more for other people.
Simple solutions are always better.