I can imagine that there are many critical bugs and the team behind is rather small. Hence the warning regarding the use of outdated keyboard component and its further development. But, if you do need to switch to Russian keyboard layout today, its probably easier to hack it together on maliit1

As for joining the effort - not yet. I am busy with maintaining own software and have few ideas that I would like to explore first to make it better. However, I did make sure that it should be easy to port the maps server to Nemo by adding QtQuick GUI as one of the frontends. As far as I understand, that should help. And, when working on something, looking on whether it can be applied to Nemo as well - such as work on keyboard predictor. But, yeah, sorry, would prefer not to get involved directly, yet, and work on other projects.