As a Trot who has been to China, maybe I can contribute here. Fortunately I've never heard a comrade say we must "stand against China", I don't think any serious Trot would say that, although there are some ignorant people out there. They would hopefully be more discerning and say something like "we of course stand with the Chinese proletariat, the people who have actually produced all the amazing developments in that country over the past several decades, while critiquing its bureaucracy". But above all we'd repeat Karl Liebknecht's slogan "the main enemy is at home". If you live in the US, your main enemy is the American ruling class. In the UK, the British ruling class, etc. If we live in the West, we do indeed have bigger priorities than critiquing the nomenklaturi of nominally socialist states, but we are internationalists and have to examine what is happening around the world. We definitely have to do it in a way that avoids the pitfalls of US State Department talking points, like the whole "debt trap" rubbish. I mean, all that was just regular capitalist business deals.
Having been to China myself, I can't help but agree with the characterisation of China as a capitalist restorationist country - wage labour is still the way things are done, the proletariat doesn't own the means of production, and minumum wages can be very low even in Shanghai (approx. $370 per month, which even considering the massive cost of living difference with the West is a tight budget). Wealth inequality is increasing. Certainly many workers have better conditions now than in 1949, or during the Great Leap Forward/Cultural Revolution, but economic well-being doesn't equal someone's relation to the means of production. And I'd never support "regime change" in China, actually there's potential for a move back towards socialism and workers' democratic planning, but also interests counteracting that. It's a fascinating place, I wish I had more time to properly study Mandarin. Can recommend the film "We The Workers" for a look into the present class struggle there.
The China Drama channel on YouTube