A guide to China's domestically produced smartphones?

I'm really interested in HarmonyOS and other Chinese domestic market (CDM) phones and OSes after reading so many discussions about Huawei, Vivo, and OPPO phones. I was hoping we could compile some details on them and how one might get one from outside of China. A place where we could discuss the advantages, disadvantages, and distinctions of using them on a daily basis, perhaps with some reviews?