First, let me thank you for the insight, it's valuable! To the PU wheels - polyurethane wheels are rubber wheels, so we're on the same page there. Weight capacity-wise, it actually differed from country to country, depending where and which certification did the manufacturer pay for to be tested for. I did go with babyartikelcheck's information that it's up to 15 kg (https://babyartikelcheck.de/kinderwagen/hartan/i-maxx), but I agree it's anyway not suitable for kids larger than 15 kg. Let me correct this on site in a few moments ;-)
Lastly, I will update the dimensions as well, thank you for that ❤️ Have a great day, and don't hesitate to write us any insight you might have, it's very much appreciated.