I’ve always been underwhelmed with the Analog Keys joystick - short, thin plastic stub that felt awkward to hold.
I found that Barefoot Buttons (the guitar pedal switch toppers) fit pretty well with their set screws. I first tried their ‘standard’ size, but it was a bit large. Their ‘mini tall boy’ is smaller in diameter but a little taller, and I think it’s a perfect addition to the joystick.
Related: I wish the joystick had more resistance. I’m currently searching for a ‘conical spring’ that would fit around it, secured down by this BB cap, to give it some extra resistance. Will post if I find something that fits…