I own MSFS since day one and I'm using it for GA only. But I did not purchase any MSFS add-ons except four small ORBX airports. I've purchased/upgraded many many Aerosoft titles for P3Dv4/v5 and I would continue to do so ... But unfortunately, I'm part of the minority, and minority does not count for Aerosoft.
I've seen a video today where it was described that only three values in Alpha Test section of the corresponding .bgl files have to be changed. Alpha Function "GreaterEqual" to "Never" Alpha Test Level "0" to "1" Z-Test Alpha "True" to "False" I'm not sure if this covers the whole problem. But if true, then it seems not too difficult to change it.