After being disappointed with the previous buck converter, this one actually seems to deliver what was promised. The specs at the Aliexpress shop indicate it is good for up to 10A without extra cooling, and that seems reasonable in my test.
I finished a video about the cheap Yiyelang “30A” 24v to 12v converters found on AliExpress:
As expected, the magic smoke is released at the end. Enjoy!