The v2.2 has been released and it is time to open a new thread for the v2.3. This is a small pre-view of what has been already developed for v2.3:
The first image is normal path tracing, the second is hybrid forward/backward path tracing and the latest is hybrid forward/backward path tracing with SDS path cache (i.e. caustics seen trough specular surfaces).
All the images where rendered using a GPU. The first two rendering modes are already available in v2.2, the latest in v2.3.
In the meantime, we are also collecting idea for v2.3: https://forums.luxcorerender.org/viewtopic.php?f=5&t=1454