I've had a TM T.Flight Hotas X for years and it works perfectly with FSO (deadzone issue, really? Haven't noticed). BIG NOTE: be sure the joystick's switch is set to PC, NOT PS3 and the LED throttle button is GREEN [4-axis], not RED [5-axis]. If you have to change the switch settings, you'll have to pull the USB plug and plug back in to let Windows redetect it after changing the switch from PS3 to PC. Also, make sure the joystick is fully functional under Windows by calibrating it (open the "Set Up USB Game Controllers" applet in Windows 10/11). The joystick should show up in the dialog box with a Status of OK
Now, you can click the Properties button and test all of the buttons and axes (you should see joy control, Z Axis, Z Rotation and Slider controls as well as 12 buttons and a hat switch tester). If you feel you need to recalibrate it, go to the Settings Tab under Properties and click the Calibrate button. Read the instructions and do whatever the calibrater dialogs ask you to do while clicking Next after each step to calibrate each axis. After calibration is complete, go back to the Test tab and test all of the options on the joystick again to make sure all of the buttons work and axes move.
Now you can start Knossos and go to Settings and under the Joystick option, make sure it sees the same joystick Windows sees (T.Flight Hotas X). Uncheck all of the force feedback options (not needed here). The final step is to go into the game and use the BIND option under the joystick configuration options to BIND certain joystick actions to either an axis or a button until all of the buttons and axis controls are set to their preferred controls - with the axes set to X+Y on the stick, Z-Axis set to throttle and Z-Rotation set to roll craft. The HOTAS X has a rocker on the back of the throttle that can also be used to roll the ship - use which ever you prefer to roll: twist the stick or use the rocker lever.
Hope this helps.