Joinmarket developers, your software has been around for a couple of years. The documentation still sucks. So does the user interface, if you can call it one.
Have you considered doing some usability studies? Nothing fancy, just grab three or four friends/relatives/neighbors, ask them to install and use joinmarket with NO HELP FROM YOU while you quietly and patiently watch.
Then act on what you observe.
If you don't want to do the above, then would you please change the title of this thread? Make it "Coinjoin that hardly anybody will actually use".