I just realised I need to release a devfiles update before map makers can access the new ERC 479 pickup, sorry for the delay there. You'll now be able to place that in any of your levels that you want it to be available.
That's the main change for map making that I can think of. As usual, this development files update will also encompass all the changes to the main game since the last, so you'll now have the new character model among other things.