James, How is this rewrite going. I have a similar issue. I have four older PCs that I was intending using for helping with the rendering and a more powerful laptop as the master. What I am seeing is that the load balancing is very slowly creeping towards the correct value, but currently the slower PCs holding up the system. Each frame takes 1min 35secs to render. If however I just use the laptop on its own it takes 14secs. So a mode of one frame per computer, with the first to finish getting the next frame would suit my setup. Details of my setup: Blender 2.90 CR 0.2.6 Slave 1: i7-7700 16GB GTX1050 Load balancing = 0.14 Slave 2: i5-4460 8GB GTX750 Load balancing = 0.07 Slave 3: i7-4770 8GB GTX980 Load balancing = 0.36 Slave 4: i7-7700 16GB GTX1050 Load balancing = 0.16 Master: i7-10750 16GB RTX2070 Super Load balancing = 0.24 I have tried manual balancing, but still get slow rendering times.