You can improve the quality in recent versions of Unreal (5.3) but it won’t be perfect. It will get better over time I guess.
Enable Hardware raytracing and tick the box that lumen should use it in the project settings. Then add a post process volume to the scene. You can add a smaller post process volume with a higher priority to limit the high-quality reflections to rooms that need it. In the post process volume set the reflection to High Quality, “Hit Lighting” and increase the bounces.
The post process volumes are camera based. So, the player (camera) needs to be inside the volume to be effected by the volume.