That's pretty sweet. I'm just learning Kicad, and I didn't know about the 40% reflow rule, so thanks for that education.
For the past 25 years, I've tried to avoid proprietary closed-source tools for my software work, and now I think hardware is getting closer to having totally FOSS tool-chains, including FPGA programming and silicon chip design. I'm not exactly "looking forward" to using FOSS equivalents of what you've shown here, but I do like the idea of having reliable automated routing and layout tools in FOSS tools, like Kicad.