MLMs don’t support the PRC after 1976 as they view the defeat of the cultural revolution and Deng Xiaoping taking power as what turned China onto the capitalist road, and often critique it as being social imperialist . Mao Zedong thought this of Deng as well .
They do, however, defend China insofar as it’s against Western-imperialist lies - but they view China and Russia as forming an emerging Eastern imperialism, and that being the source for said slander campaign, that it forms competition to the current imperialist hegemony - not because they think the two pose a threat to the capitalist-imperialist system in general.
I think Maoism can either refer to Marxism-Leninism Mao Zedong Thought (ML-MZT), or it can refer to Marxism-Leninism-Maoism (MLM) depending on the context - these days it’s mostly used for the latter