Maya LT is almost the same as the full version of Maya, the tools that don’t apply to gaming are removed, like some rendering and simulation stuff, but the stuff like modeling and texturing are still there.
As for file formats, I’m not sure if there’s any difference between the Maya LT files and the full version of Maya, Educational licenses have the exact same version.
Also as far as the 65k limit goes, Unity doesn’t use any restricted file format, I’m guessing you could “export to Unity” and then just find the file it exported and import that to UE4, it should just be like an FBX file, there’s nothing in the file that makes it only work in Unity.