I think most compatibility problems would be solved by ignoring the terrain tag on tiles with star-passability. replace the terraintag method as such (in a new plugin)
Game_Map.prototype.terrainTag = function(x, y) {
if (this.isValid(x, y)) {
const flags = this.tilesetFlags();
const tiles = this.layeredTiles(x, y);
for (const tile of tiles) {
if ((flags[tile] & 0x10) !== 0) {
// [*] No effect on passage
// we skip terrain tags on star tiles here because
// they now mean something else.
continue;
}
const tag = flags[tile] >> 12;
if (tag > 0) {
return tag;
}
}
}
return 0;
};