A possible solution that could really solve this issue very fast and with great accuracy, could be a suggestion another user described here:
https://forums.flightsimulator.com/t/terrible-night-lighting-after-patch-5/310086/181 (He describes a way that could be used to filter out rural roads and secondary network infrastructure by implementing an inverted Black Marble NASA imagery filter (the same used for the sepia night filter for cities by Asobo), over the OSM vector data)
I don’t really know if it’s possible or not for Asobo to implement a filter like an inverted Black Marble NASA imagery, over their vector-road data. This could possibly solve this issue without the need of specific OSM parameters for exclusive regions.(It could certainly be done via changing road parameters in OpenStreetMap , but realistically it would take decades to correct them and categorise them correctly for large parts of the world. )