Now that we are ready to proceed with the steps to make a much less complex version of a TIN surface as a CVX vector sloped flatten in SBuilderX, you will need to install a specific 'scenery utility' add-on aircraft into P3D.
I think I have installed them correctly. I downloaded the "crosshairs plus " folder and moved it into P3D aeroplanes folder, then I downloaded the "Panel and model" package and replaced the old "crosshairs plus" files with the new ones given inside the "panels and model" package. So I believe I have installed them correctly
Assuming you have also downloaded and added the missing texture for Jim Robinsons updated FSX compatible model of CH+, and that you have verified its FSX format MDL will load in P3Dv4.x as a user aircraft listed under "Finney Ground", I shall post further instructions when I get back (...I am on the road for another hour or two).
PS: Take CH+ for a 'test flight' in P3Dv4.x ...it is a newly skinned livery of a unique legacy FS aircraft flight model known as "JetPack Man" :-D