I'm sorry that you're having problems with the most recent 2.7 releases. I know that there were some early problems, but I've not noticed / heard of any problems with 2.7.12 (released on Dec 18).
I know that some projects maintain a "stable" and a "development" version. However, maintaining multiple different releases of the code is difficult task and can easily lead to errors, and thus the decision was made several years ago that the very limited developer time (there are three of us, all working on this part-time) was better spent fixing bugs and providing user-support in the latest code, rather than trying to back-port fixes into old code.
Can I ask, what was the problem with "Scored" merge? Document is only really useful where the paragraph structure is identical, e.g. a transliteration project or strict back-translation.