The comment says
I don't know if that's the information you need to fix your skeleton. All these had to be rotated 180 to look correct in blender, then back 180 the other way when exporting to not make the guy look that way. It's not mirrored bones and it's not all the bones so I have no idea what it's caused by.
As for 2.80 compatibility it's probably just changing __init__.py to match 2.80 expectations (mainly it includes a target version, script has 2,71 and that needs to be minimum 2,80) but I'm not really using 2.8 so I haven't done it.
Code:
version = 1.0
# this is the bones that are, for some reason, rotated 180 from how blender has them.
negabones = ['DRIVER_RIG_Leg_L','DRIVER_RIG_Shin_L','DRIVER_RIG_Hill_L']
negabones += ['DRIVER_RIG_Leg_R','DRIVER_RIG_Shin_R','DRIVER_RIG_Hill_R']
negabones += ['DRIVER_RIG_Arm_L','DRIVER_RIG_Shoulder_L','DRIVER_RIG_ForeArm_L']
negabones += ['DRIVER_RIG_Arm_R','DRIVER_RIG_Shoulder_R','DRIVER_RIG_ForeArm_R']
negabones += ['DRIVER_RIG_ForeArm_END_L','DRIVER_HAND_L_Thumb1','DRIVER_HAND_L_Thumb2']
negabones += ['DRIVER_RIG_ForeArm_END_R','DRIVER_HAND_R_Thumb1','DRIVER_HAND_R_Thumb2']
negabones += ['DRIVER_HAND_Index1','DRIVER_HAND_Index2']
negabones += ['DRIVER_HAND_Middle1','DRIVER_HAND_Middle2']
negabones += ['DRIVER_HAND_Ring1','DRIVER_HAND_Ring2']
negabones += ['DRIVER_HAND_Pinkie1','DRIVER_HAND_Pinkie2']
negabones += ['DRIVER_HAND_Index4','DRIVER_HAND_Index5']
negabones += ['DRIVER_HAND_Middle4','DRIVER_HAND_Middle5']
negabones += ['DRIVER_HAND_Ring4','DRIVER_HAND_Ring5']
negabones += ['DRIVER_HAND_Pinkie4','DRIVER_HAND_Pinkie5']
# and this is the matrix that rotates 180 around X to fix it during export
halfrotmat = mathutils.Matrix.Rotation(math.pi,4,'X')
I don't know if that's the information you need to fix your skeleton. All these had to be rotated 180 to look correct in blender, then back 180 the other way when exporting to not make the guy look that way. It's not mirrored bones and it's not all the bones so I have no idea what it's caused by.
As for 2.80 compatibility it's probably just changing __init__.py to match 2.80 expectations (mainly it includes a target version, script has 2,71 and that needs to be minimum 2,80) but I'm not really using 2.8 so I haven't done it.