When editing with Nauvis as the surface, entities placed are placed as if you were in creative mode. This applies in both multiplayer and single player.

Tested how it works in multiplayer, and it does cause desync among players when editing a blueprint.

Hi, what do you mean editing with nauvis as the surface? The editor is in a different surface. Do you mean you were already in map editor in nauvis? I don't understand, sorry

https://imgur.com/uffejHk

When using the surface option from this menu and selecting Nauvis instead of the default tiled background, items can be placed in world as if you were in creative mode.

Well sure, of course, you're in map editor mode. The editor is almighty and you can do pretty much anything with it. You'll have to be a bit self-disciplined to not cheat in your nauvis surface :D

Oh wow I completely misunderstood that page and thought it was just so I could create a blueprint in world. Would it be possible to create a setting to disable map editor mode?

I don't really find that useful or sensible, but I'll think of doing that in some simple way to add a setting.

In the end I decided against it, it removes too many things. Just don't cheat in your main surface, it's not that difficult. :)