From what I understand, it is *specifically* the 630 (and some 5xx) iGPUs that have this issue. No real Mac without a dedicated GPU has one, as Apple uses the Iris Pro iGPUs available in the -U CPU models. If someone can point me to a case where someone can demonstrate a system with only a 630 and no dedicated GPU successfully sleeping and waking from sleep, I would love to see it; I have attempted to get it working for about 8 months now, and every single thing I can find says it's simply not possible with this specific model. Sleep is no problem; wake will always hard lock (to the point that not even the case reset button works, must completely power off and back on) or result in a kernel panic. I'm currently using iMac18,1 as that is a model with the same chipset, CPU family, and no dedicated GPU, but it really doesn't matter, other defs cause the same behavior for me (if they don't break other things in the process, heh.) I've also specified the ports, pipes, and framebuffer configuration as per
https://www.tonymacx86.com/threads/guide-intel-framebuffer-patching-using-whatevergreen.256490/ to precisely match my actual hardware, have full CPU/iGPU PM functional, etc., so at this point I'm reasonably certain it's not something I missed in my setup...I'm always open to the possibility I'm totally wrong however (sure wouldn't be the first time, hah!)
