As you talented cartographers might have noticed, mapping tool does not provide ability to disable world wrap for player made map. So here's how to do this manually:

Enter directory with your creation at Documents -> Humankind -> Maps, then unzip your .hmap like it's a zip file. Inside you'll find Descriptor which contains information like amount of players or map size for game to properly launch the lobby with map. The other, Save.hms, contains information related to how map looks in editor and in-game. Open it with text editor of choice.

1.0.2.166 Steam beta branch added world wrap setting in editor.

Skip to <Document> to find <Width> and <Height>. As of now limits to how big map can technically be are unknown After testing, approximately 21,750 tiles were rendered before game engine started bugging (145x150). Plese use this as reference value, if you manage to get more tiles rendered, please tell. <UseMapCycling> determines map wrapping. True for wrapping, False for borders. After that, save file as .zip format, using Deflate as compression method. Change map's format to .hmap and enjoy mapping!

Making use of border wrap:

In editor map will still wrap, so first you have to find out where the borders are. For that you can use a simple graphic with two rectangles of other colour to import into editor. This way borders of map will be of different elevation and easily visible. Use "never seen" brush to mark these spots, so that they won't get lost during map making and you're free to import/create freehand whatever map you want!

With all this noted, have fun building maps and scenarios of your dreams!

Using 7zip, select the two extrcted files, add to archive, change then name, make sure to select zip format in the settings(not 7zip, both having same extension)

The Deflate option will appear in compression methods if you chose zip

Compress

Then you can change the name to hmap and put it back to where you took it in the map folders

You can also use bhkmap tool by Benualdo (See this forum for link).

Disabling Wrap now works.

However, I think you need to set left and right edges as the dead zones. Not the poles like the Map Editor says. Poles are fine AFAIK. It's cos on a hex map there is no straight vertical line. It's a zig zag. Like in Civ VI. So units zig zag off the edge of the map (North Africa here in the screen grab) which looks a bit jarring but that's all LOL