I just downloaded your p3d_xml_vars_x64 but can't get it to work. I first put the p3d_xml_vars_x64.dll in the P3DV4 root folder and added a popup window in the panel.cfg file per the text file included in the download. See below:
window_size= 0.273, 0.352
window_pos= 0.000, 0.050
All I got was the black background with no Lvariable data. I then moved the dll file to the gauges folder and changed the gauge info to
gauge00=p3d_xml_vars_x64, 2,2,350 with the same result. Can you or anyone provide me any insight how to gets this gauge to display the data. It sounds like an incredible tool.