I’m currently trying to get an Xbox 360 controller and the controller at the below link working
https://www.bhphotovideo.com/c/product/758789-REG/Thrustmaster_2960703_T_Flight_HOTAS_X.html
On the Xbox 360 controller the first two axes are the left stick and the third and fourth axes are the right stick.
On the HOTAS controller the Flight stick is the first 2 axes. The Third axis is moving the throttle back and forth. The fourth axis are two analog buttons on the front of the throttle that are pressed left and right.
I think the issue in MagicDOSBox is in this section:
https://www.dropbox.com/s/3oshmzgm6ewsbol/Screenshot%202020-07-22%20at%207.01.54%20AM.png?dl=0
You only have the option to map the first two axes.
On windows the 4 axes works out the box.
To quickly test the joystick axes in MagicDosbox I use the joytest.exe program at this link(Not the joycheck.exe program. That one gives me issues).