It seems like the new rendering causes beacon beams to not render if the beacon block itself is "optimized out".

Steps to reproduce:
1. Start a normal world (I would suggest in creative mode).
2. Dig a straight hole between the sky and bedrock.
3. Build a small beacon down there so that the beam goes out through the hole.
4. Go to the surface and look in the direction of the beacon.
5. Move your gaze so that it points slightly upwards towards the sky.

Result:
The beacon beam stops rendering and disappears from view.

Expected result:
The beacon beam should continue to render since it still exists, is active and serves as a waypoint for players.