Is there a way to import a model with quads and retain the topology without turning the quads into tris?
No, all of the geometry will be in tris
To expand why:
The video card will treat the object as triangles no matter what.
Quads often are not flat and there’s 2 ways you could split them, which often changes the shading/smoothing/normals.
Different applications will convert models to triangles in different ways, so normally you’ll want to triangluate your mesh even before importing it into UE4. If you are working with baked normal maps, you’ll want to triangluate your low poly model before baking.