OK, I’ve just seen that post and added one for the iron I’m using. The original 70den/170gsm tpu fabric I bought 5 years ago from extremextil welds very well at a temp of around 280C, but the new lot just melts at anything more than about 160.
It seems to me that anything extremtextil do not list as “high-tenacity 6.6” is only “nylon 6”. Matt mentions the difference somewhere on this site, and I will not trust the “6” for anything. If you bounce on a sleeping mat I would expect it to break and leave you on the cold ground for the night; if your raft bounces against boulders at speed then I would rather be on shore with a camera than in the raft trying not to drown.