It seems it will NOT work, they said it:
I think they decided long time ago to not work on 1.5.x version and put the effort on 3.x, fair enough. However, after more than a year, the 3.x version is not usable at a serious level. Some huge issues like memory leak and high CPU usage have been there for months and they release new versions explicitly stating that the releases do not address those problems.
So, we may be on a dead-end here @Vladimir_Oka unfortunately.