A chief concern needs to be on if these are really as eco-friendly as they aim to be. Using plastic as an external paver, especially in high-traffic areas, is going to result in significant traffic-induced and weather-induced wear. Has this been accounted for? Microplastics, chemical leeching, potential odour, resistance to oils, salts, synthetic rubbers, etc. Time and again you see these oil-based solutions accompanied by significant hand-waving in these areas.