Just make it into a *.t3d, that’ll be fine.
The nomenclature would follow the name of the map in the editor, so, so long as your maps are named correctly, that will be fine.
They are tiny text files, and reference the location of assets, plus, use the world positional data…not much to them really, but they are very powerful formats.
Only thin I’d worry about structurally, would be if you are using power of two or not, as any mis-match in project settings (like references) will cause issues with actor/object locations.