After reading this and clicking around the site I'm still not entirely sure what these machines actually do. Apparently they grind up hard plastics and turn them into pellets? But similar machines already exist as a commercial/industrial product that can easily and cheaply (from $500) be bought from Alibaba etc [1], so their differentiation is that their machines are open-source? Which is useful how, exactly? Their Pro page estimates EUR 2000+ in parts alone per machine, plus you need to cobble the things together yourself.
[1] https://www.alibaba.com/showroom/plastic-recycling.html
[2] https://www.preciousplastic.com/solutions/machines/pro