Console access in the map editor

[zx64]

The main things I'd like to do with a map editor console are:

• Custom scripts for tile and entity placement
• Setting properties of multiple entities

Although I suspect it'd expand into "pretty much anything you can do with a LuaSurface".

I am able to do these things indirectly by starting the scenario, run my scripts, save and convert back to scenario format, so this wishlist item is more about streamlining an existing process.