If you design your game engine the right way,
then you can re-use your displaying/drawing code in a dedicated game editor.

It won't do feedback from inside the game, but at least you can design your game in a more visible way than editing spreadsheets/xml/textfiles/script/whattever, and then test-run the game.

Going even further, you can add editing features in the debug/development/testers-build of your actual game

There's plenty of possibilities, but they'll all require some effort in coding to get done, for one-use game engines, this may be overkill, unless you have a LOT of level desining to do. I've seen enough technically simple games, but with hundreds of different game levels/zones/missions. If the 'level designing' ends up being the bulk of your development work, then yes, this might be worthwhile.