X52 axes for pitch and roll either 0 or 100%
The issue is solved!
It appears this regedit for re-calibration of off-center axis resolves the issue:
https://support.logitech.com/en_us/article/Recalibrate-controller-axes-RegEdit
For future readers if this link no longer works, here is the entire contents of the .reg file:
Windows Registry Editor Version 5.00
[-HKEY_CURRENT_USER\System\CurrentControlSet\Control\MediaProperties\PrivateProperties\DirectInput\VID_06A3&PID_075C]
[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaProperties\PrivateProperties\Joystick\OEM\VID_06A3&PID_075C]
It appears to be clearing the value of "VID_06A3&PID_075C" (the hardware ID of the X52) from the registry. I did uninstall the drivers, but I guess this value stuck around. At some point during driver installer, it must have set invalid values here.