Well, i have good an bad news.
Good ones first : I think i’ve cracked how to add GI for particles at an acceptable time. Will probably be a high end , as the math tell me ( computing numbers out of the amount of rays I can cast per second, about 300 million/second (need to re-check that number, it’s old, might be more now) ) that my GTX 750 Ti will take about 1.75 ms for the low quality preset (lighting computed at each vertex of the quad. Actually, it’s a bit more complex, but the lighting will be sampled at vertex level) and a high quality preset at about 4 - 5 ms (lighting sampled at pixel level, 6 rays spherical interpolation, the same thing i use to get the normals to show in GI ), for each particle system.
The bad one is that due to the fact i’m only one guy, i need to prioritice time. I have exams coming in a few weeks, so the time I work on is after studying quite a lot, therefore I want to do some fun stuff, like new features, particle lighting, better interpolation, multiple bounces, etc, and updating to 4.8 is going to be a tedious (and maybe long) job, so I’m postponing that until late july-early august, when my exams are mostly over and I can have some more time. Want to push features first, or at least make some more work on them. I know can be a problem to the ones that want AND the features on 4.8, but hope you people understand the.