I have done a fair amount of night navigation doing SAR operations (they almost always occur at night), but without the constraints you faced. We could use trails and the whole point of our presence was to be obvious.

Again, in mountainous terrain, compass use was rarely required, but a good topo map was essential.

Agreed. I'd like to rephrase that into that in such terrain the compass primarily is a backup for when you find yourself in a state of geographical confusion, either because you've made a map reading mistake or there's limited visibility.