Yes it is possible. You can use PolygonGraphics with heightReference set to CLAMP_TO_GROUND. You can also use GroundPrimitive, which automatically drape over terrain.
My apologies, that is the correct link.
It is possible as noted in this discussion.
I have previously made an example for primitives here. I don’t recall seeing an example for entities.
Thank you for sharing your use case. We look forward to seeing the results and assisting you further with the project.