Since china buy up most of our steel and ali scrap which is then exported to them, if the products are able to be certified, then they could be as good. Chinese product quality is determined by price and demand - so if Thomann are selling the stuff, then the liability is theirs too - so would they sell untested product within the EU? No doubt test results will appear soon. Even CPC are selling Global truss now.
Remember though, just because it has a Safe Working Load of Xkg it doesn't mean it's good truss!
Cheaper truss will be more prone to damage. Once truss is damaged, it doesn't have a SWL of anything.