GDevelop now supports tilemap painting with collisions. Read the release notes here: Release 5.4.207 · 4ian/GDevelop · GitHub
I noticed that there is no support for ldtk collisions. this would not be hard to do, because ldtk has enums, which seem to work the same as in tiled. Also, in my opinion, ldtk is better for this anyway, because it is more intuitive, easier to use, and is constantly getting updated, whereas tiled looks straight of the early 2000s.