Proof of onward travel

Hello, I would like to ask about the L tourist visa for China. I am from the EU and currently a student in South Korea. After finishing my semester I want to travel to mainland China from South Korea and then travel to other countries from China before ending my travels in the EU. When applying for the L tourist visa, I will use my Korean student visa as the legal permit of stay. My question is, is it a problem that I am not gonna have a round-trip flight ticket to South Korea but a one way ticket from Korea and then another onward travel ticked to another country? Basically I am curious whether it is important to specifically have round-trip tickets or if it is okay to have leaving tickets for a third country that is not my country of origin. I keep finding round-trip tickets everywhere as a requirement. So I am curious whether it is only important to have a proof of onward travel and therefore a proof that you are gonna leave China or if they are really doubling down on the round-trip tickets to the same country for some reason. Thank you!