Is this the necessary procedure?
Step 1: Connect the extension cable
Step 2: Plug it into the computer
Step 3: Connect the headphones
Is this mechanism exclusive to the CS43131? What about other chips? For example, the CS43198?
Enough to meet your needs. KA11 is also a good thing but not as cheap as JM20 MAX in my country.
You can also take a look at JM20 Pro, which has a mobile APP that can adjust PEQ.