2461? are useless, my bet is that there was idea to connect two S5KM312CL as master/slave (you can connect up to 4), and it should work nicely however there is something wrong with firmware and nothing of it is working as expected, there is super ghosting, literally ghost are walking in empty room, targets are duplicated, reflected etc.
You can see here my few experiments, but lastly I received TI IWR6843AOP, and man, it is expensive but support, software, minimal lag - it is top tier.
About LD2450 you can look here too: HLK-LD2450 Initial experiments to connect to HomeAssistant - #470 by wojciech6789
@tieppm1 there is nothing in inbox from you