We all know, that the GameMaker's built-in editor is an abomination that should be burned, buried, and the trees that grow on its ashes should be burned and buried as well. There are not that many ways of creating decent maps based on tiles either (two, including Tiled?), that's what makes Tiled an editor of choice for people who use GameMaker.
There are converters, scripts and whatnot, that technically take care of it. Except half of them is outdated, quarter doesn't work, and the is too confusing and doesn't even have a how-to.
Hence my question: it is a planned feature? If not, can it be a planned feature? If not, what other engine with a sane map editor/Tiled support can you recommend?