I received the newest milestone for lxqt earlier here on sparky and testing than via siduction. I performed a dist-upgrade and for me, no major problems noted. I did read up on debian bug 792321 and chose to go ahead anyway. For me it is a fresh install of libkf5screen6. The lxqt updated versions are 0.10.0-1 from 0.9-6
Things could still go wrong for others on different architectures. This was done on an atom 386 netbook without kde5-plama5 I use sddm on this machine instead of lighdm.
There is a steady progression of adopting tier 1 kf5 components
QuoteThis release, we focused on cleanup, polishing and quality-of-life
improvements, with over 400 issues fixed and dozens of new
translations. We have also gained two new frameworks: Solid, which
replaces liblxqt-mount and some custom power management code and
libkscreen, which replaces system xrandr calls and is wayland
forward-compatible.