There hasn’t been any relevant progress on this front last year. The optimizations implemented in the backend in summer (FT8/FT4 spots & backend scalability) have completely obliterated the scalability issues for the foreseeable future, so the pressure to change something in the architecture has been greatly diminished 
I’m still reluctant to work on larger new features, mostly because the UI is really outdated and clumsy to work on. I guess that would be the first thing that should get rewritten.