The simulation components are initialized prior to the map generator.
So we can simply add getters to the map generator JS interface in MapGenerator.cpp
.
MAP_BORDER_WIDTH
is a special case because the simulation doesn't have a central place for this yet and instead hardcodes that magic number all over the place, see #4636.
Other components like simulation/UnitAI/PlayerAI, Atlas might also need some parameters so further comments welcome!
For the simulation people already take care not to copy magic numbers and it's easy to access C++ simulation constants from JS simulation components. Not aware of any existing hardcodings in the JS sim.
For atlas, we have
tools/atlas/AtlasUI/ScenarioEditor/Tools/PlaceObject.cpp:static float g_DefaultAngle = (float)(M_PI*3.0/4.0);
Not aware of any other atlas hardcodings. (One might or might not argue it doesn't have to be the same default angle for atlas and random maps.)
the direction changed, see map.js getMapData
Don't see anything changing angles there.
Edit: it's in getFullEntityList