Please find attached some MFG files (WF3.0 M250) to help you to deploy your 4 axis PP.
I have made some changes in that original post from the link to make it a 4 axis one. It works! J
Eventually you may have to change the direction of the rotary. You can change it on the dialogs shown below:
In the OFG (Option File Generator), I think that changing "Default dir. CLW" is enough. The other settings usually don't need to be modified. Please check GPOST context help to understand what they do. If your Haas is set to use shortest moves, then you may have to change the PP as well. This can be easily done through the OFG.
Make sure that your workcell settings are like shown below. If you change the direction in GPOST, change it accordingly in the Workcell as well.
Last but not least, I attached a video showing you the verified G-Code using our NC Editor (Really good for Haas machines) and a MFG Template with the original toolpath and the references for the Workcell settings.
I created this template quickly to exemplify how you should set your workcell and coordinates systems/axes in a Hass VMC with a 4th rotary around X. It does not have much features, but it's a starting point.